You say it’s for personal projects but if you care about marketing then I’m going to guess the projects are serious/ambitious enough.
In that case, as you build them, you’d probably first need to do some “marketing strategy” early on, then naming and branding, then some growth marketing/product design, then see how you would incorporate different types of analytics into the projects, then finally there would be a launch and running some campaigns and using the analytics methodically.
I’d say anything less than that would not really be any kind of methodical marketing. But people do get lucky with word of mouth sometimes.
So, basically, you could probably use a good amount of modern marketing skills.
The internet is, of course, full of options but it’s hard to filter through them.
Based on my watching this space for about 10 years, most of the one-person shops and small teams that do SEO and Wordpress websites will know very little about those things you’d need.
Maybe 1% of medium and large firms out there will work with that stuff in SaaS space but then they would likely be way too expensive for personal projects.
Which leaves you with two options IMHO, 1) to learn that stuff yourself (the path I took), or 2) to find a marketing/product/growth cofounder/advisor/consultant that has experiences in that niche, such as SaaS, for example.
Good luck