How would invest 10k$ in your 30s?

Depends on the situation, but I think general advice would be to do one of two things based on the assumption that you're in your 30s and don't already have a solid plan on what to do with 10k on your hands:

1. Invest in yourself. Start a business, take some classes, try to upgrade your current job, etc.. Improve your work situation so that the 10k turns into easily 100k of earnings over time. Or use it to improve your health, saving money long term in health costs. Whatever. Investing in yourself is usually the safest bet you can make.

[Edit: 1.5 - forgot the generic personal finance advice - if you don't already have an emergency fund, use this to create it. Just put the 10k in a savings account to have a bit of liquid cash on hand in case something bad happens and you need it fast. If you're good there, but you have any very high interest debt, pay that down second.]

2. Put in into something safe-ish with good growth potential, like VTSAX, and save it for a rainy day. Maybe start a retirement fund if you haven't already.

I would put 7-8k into VTI with the intention of letting it ride forever(ish). Then put 2-3k into some stocks that you like

I keep reading about series I bonds paying out 7% and tax advantaged, but unfortunately never patient enough to actually read about how it all works. 10k is the yearly limit which is why I mentioned it.

Pay down debt

Dunno what but do it through your Roth IRA and HSA since that is right around the limit for both.

$6000 into Roth IRA into VTSAX or FZROX.

Then General investment into VTSAX or FZROX.

buy ETH, before watch this vid https://www.youtube.com/watch?v=b1m_PTVxD-s

Half into a house and half into a Roth IRA.

I would buy 25 shares of QQQ