If you are setting up a base station, your landlord or HOA may have restrictions on the antenna size. There are no permissions or license required in the U.S. from the FCC assuming you are using unmodified CB radios. Keep the antenna and coax cable away from other equipment if you can, to avoid interference that results in neighbors complaining about you.
Technical:
Look for ARRL sites that describe how to properly install and ground your antenna as well as different antenna types. The same knowledge for ham operators using the HF bands will apply to CB radio (26-27Mhz). HN is not a sufficient platform to give you all the steps you would need. You will need an antenna, SWR meter (standing wave ratio) to tune your antenna, coax cable, antenna mast, grounding connection (new or existing building ground). An all-around decent omni-directional antenna would be a 5/8's wave ground plane. 1/2 wave are more plentiful but less effective for what you are doing. The ARRL sites will give you information on how to do all of these things. You could also find a local ham radio club that will have people knowledgeable in this area. They may try to get you into HAM radio and that does require a license.
There are CB radio base station transmitters. The selection is smaller today than in the 70s/80s. You can find equipment on Amazon, just don't trust the positive reviews in my opinion. Try to find something that has both AM and SSB (LSB USB) should you some day want to talk to other countries using skip conditions.
You will find truckers and maybe some locals on channels 17 and 19. Channel 9 if for emergencies but may not have anyone responding. Happy to add more later, but I have to step away for a bit.
I would suggest not limiting yourself to just CB. Look around for your local amateur radio club. The basic exam is not tough and it will put you in instant contact with loads of other radio nerds keen to chat. With a HAM license you'll have many many more channels to play/work with. Taking the advanced exam will require more study (unless you are a MSc electrical eng) but the reward is definitely proportionally greater
Serious users are all HAMs, but then it's all "serious business".
The last I heard any substantive CB chatter was around 2014, while driving to Kentucky. Two things I recall from that trip:
1. I was able to get on the radio and ask what the source of bumper-to-bumper traffic was - it was "a chopper in the road". I figured it was CB slang for a motorcycle, but, no, this actually was a medflight helicopter in the middle of the road. So, be prepared to learn not just a language, but also context - or just use Waze, Google Maps, or your other live traffic tool of choice.
2. There is spam on the trucker channels, 17 and 19 - actual, legit spam for 10% off your next meal at Burger King at the truck stop. This accounted for a solid 20% of what I did hear, which is probably on par with the signal-to-noise ratio of e-mail.
There are a number of WebSDRs available that provide a public web interface to radio receivers located in various places. They are live streams of radio traffic that can be tuned to your frequency of choice. If you go here[1] and filter by the 10m band and the North America region, you can find several that cover the 26-27MHz frequencies used for CB channels[2]. While none of these are located in the Bay area, it should give you a sense of how active CB is and what typical usage looks like. You can also use web SDRs to listen to ham (look up 2m/70cm calling frequencies as well as local repeater frequencies) and FRS/GMRS frequencies[3] in your area.
To be perfectly honest, I feel like GMRS may be best for your use case, but the beauty of WebSDRs is that you don't have to invest in any equipment to listen. This way you can learn more about these different types of radio services and decide which is best for your use case, without lots of expensive and time consuming buy-in.
[2] https://en.wikipedia.org/wiki/Citizens_band_radio#Standard_c...
[3] https://en.wikipedia.org/wiki/General_Mobile_Radio_Service#F...
Also look into the sibling comments about Ham radio. The lowest class license is really easy to get and gives you pretty wide permissions on various bands.
Ten Four Good Buddy
Breaker One Nine
You got your ears on
That’s a big Ten Four
Good Buddy.
Double Nickels
All The Way
Those in the Bay Area should check out "The San Francisco Radio Club ( 1916 - 2020 ) Celeb rating 104 Years serving the city of San Francisco & the Community" < https://www.sfarc.org/ > They are a great bunch and are, as one would expect, very knowledgeable.
I'd consider getting a ham radio license, the tech license is really easy. Just 35 multiple choice, and you just have to get 26 questions right. The tests aren't tricky, pretty straight forward, and often common sense will get you fair number of questions right.
Disaster communications and preparations are pretty common among the ham radio community. In central California there's a regular net that include fire, hospitals, police, universities, etc. It's relatively common for ham radio repeaters to have solar+battery power to survive most disaster scenarios, you can always fall back to direct connecting if need be.
To really be prepared you have to practice, so that means participating in nets, setting up your radio, and efficiently communicating. The bay area has several nets each week, with different topics/goals. Additionally hams often help with races, large events, especially if the event is outside of cell range. In fact BLM allowed races to take place on BLM land, only if hams were involved to help coordinate with emergency services. I helped with the a double century bike race and my club also helped out with some horse races. Working with emergency services, often more than one, is good practice for a disaster.
SOTA (summits on the air) is also great practice for going into a disaster zone and helping with communications. You carry your radio, power, and antenna and get points for effectively communicating.
Sure a CB can be part of disaster communications, but it would be my first choice. Might want to pick up a couple 4 packs of the family radios and distribute them to any friends/family in your neighborhood. That way as a ham you can communicate/coordinate over longer distances and then coordinate with the neighbors, even if the power is out. If there's a disaster, your fellow hams can be quite a resource, well they are a great resource even without disasters.
In central California with a 5/8th wave 2M antenna on my roof could reach repeaters just outside the bay area, all the way up to near Shasta, and nearly to LA. Granted California central valley is quite flat, and the repeaters typically have pretty good elevation around the rim.
If you want to speak to people further away without repeaters, I'd consider upgrading to the general license, it's only somewhat more technical and allows you to use quite a bit more of the HF frequencies that can get you across the country, or even across the world depending on your radio, antenna, and protocols.
So the more radios the better, but I'd at least look at FRS/Family and Ham if you are interested in disaster communications.
From my knowledge, there is no "Ch19" for ham, so you end up scanning a lot. Not ideal while travelling.
If you want to get into CB radio, just go to your favorite online retailer or truck stop, buy a Cobra 19 or 29LTD (or literally anything that fits your budget), some coax, and an antenna - either a vehicle mounted long whip or mag mount with some kind of adapter for mounting it to your roof, or a base antenna like a Solarcon A99 or Patriot PAT-12, or build your own dipole and string it in the trees or attic or from a gable, etc. You probably also want a VSWR meter to tune the antenna if it's not built into the radio.
No permissions needed.
I would highly recommend a CB that supports sideband, you will get much better range with sideband than just AM (most common CB's are AM only). However that range will only matter if those you need to communicate with also have a sideband CB. Export CB's cover different CB bands for different countries, just make sure you're using the correct band for the US. You don't want to draw the FCC or an angry ham to you by stomping on a non-CB band.
A 1/2 wave whip and a side-band CB can get you maby 6-12 miles or so. You can probably do better with a directional antenna but that gets a hair more complicated. You'll want to get SWR meter as well for HF. Even if the CB has one built-in, don't trust it for your initial setup, it's just for spot checking for coax degradation after your rig is setup.
And a word about power... hams like to flex that they will track you down if you run a linear amp/kicker on your CB. However what they don't mention is that as long as you stay in your lane they won't notice because they're too busy talking about their medical problems and radio gear on 2 meters. If you do run a kicker stay a few channels away from channels 1 and 40 so that you don't bleed over into the adjacent bands. It's also worth verifying you don't have any harmonics kicking up noise further up the band. Multiply your frequency by 2 for the first harmonic, multiply by 3 for the 3rd, on up to the 5th or 6th harmonic. Use a scanner or receiver if possible to listen on the harmonic frequencies when you key down. If you hear noise within 10 feet of your rig do more work to eliminate it or ditch the kicker.
After you get all your other bases covered... Modulation actually counts for a lot, especially on AM. It's possible to do wonders for your CB by adding a compressor/modulator combo. In a pinch you can just hook up a power mic though, but they tend to be very cheaply made. While this will not get your more range technically, it will make your voice much more legible out in the outer fringe of your range so it still helps. This is all part of your airchain/front end and so often gets ignored by hams who think it's only possible to increase modulation at the expense of sound quality. As long as you are monitoring your audio while adjusting your modulation and compression you can dial it in to be louder without being crap-tastic.
I am in Ireland, chatting with the US is not a challenge. Australia was always hard work for me.
Ham is like IT. People will turn your head online and make it sound unnecessarily complex. To start get a little USB SDR dongle and start listening in. Will cost about £5.
2I0JXA
No signals in the last 10 minutes.
[1] https://player.twitch.tv/?channel=livecbradio2&muted=false&p...
I've got one in my Subaru Legacy I stuck up by the driver's seat, down to the left of the steering wheel. The radio itself is a Uniden PRO520XL (around $50) with a TRAM 703-HC antenna (about $20) that's on my trunk via a magnetic base. The antenna cord goes into the drunk (under the rain seal - no modification needed) and runs along the inside of the car tucked under the flooring. No tools needed, just tuck it all in until it's out of the way.
The radio itself is just screwed into a blank spot my knees don't hit with the included screws (just needed to pre-drill the holes). Ground wire is wrenched down under a bolt to the vehicles frame, and the power comes from the in-cabin fuse box (for mine that was closest, right next to the steering wheel) using a fuse tap (which lets you go under an existing fuse, so no permanent wiring or soldering needed), which I got a pack of 4 of for around $8.
All in all, about $80 to get it all together and other than two small screw holes, it can all come out like it was never there if needed.
I would reccomend getting an SWR meter (around $50 for the Workman brand one I got), which you can use to calibrate your antenna so you get better reception - it makes a major difference.
On the road, it's great in heavy traffic and rush-hour, as you can often pick up (and join in, though some are more open to this than others) trucker chatter, either to pass the time or as a pre-Waze-style method of knowing where the jams, cops, accidents, and so forth are so you can avoid them as needed. As LinuxBender said, channels 17 and 19 seem to be the usual trucker channels - some places will use both, some cities will focus on one (the Cincinnati area, for example, generally seems to be all on 19).
I've never run into the "people playing with voice modification and trash talking" busterarm mentioned in his comment, but the truckers are often VERY colourful in their language and topics - I would reccomend picking up some of the more common slang they use (I used to do tech support for trucking dealerships and garages, and years ago my dad drove a box truck, so I knew a reasonable amount already when I started) as it lets you get a lot more out of CB, since they're really still the primary people on it, at least in the US.
My radio also came with and output port for hooking a PA to it (i.e. in the hood like some police cars have), and while I've tested it with a cheap Pyle trumpet style speaker, I don't currently have that hooked up because I can't quite work out a good way to run the wire for it from the cabin to the engine compartment (though there are plenty of spots inside the hood I can zip-tie in the speaker, which I've seen people have pretty solid success with) - not exactly related to CB itself, but a fun thing if you want to add function to the radio, I suppose.
This is technically not legal, but when SHTF you're not going to find anyone coming after you for it.
Join a local ham radio club, get licensed, it's the last hobby you'll ever have. There are so many things to do in ham radio.
Not so good signal, but its fun to try searching them.
This is what the CB world is about: https://m.youtube.com/watch?v=ri0o9duzlrw