Any good resources to ask basic CSS questions?

I am fighting the urge to post my very basic CSS question(s), because I'll have lots of them over the coming days and posting a new thread here every time I have one I suspect will get very annoying or break subreddit rules, etc.

So instead, I'm wondering if anybody has any suggestions as to where a person who is getting back up to speed with modern CSS could ask questions. Are there any helpful Discord / Slack channels, etc?

I guess while I'm here, I'd also be interested in any general advice for somebody who at one point was relatively comfortable with CSS (understood a lot of the fundamentals pretty well, box model, floats, etc), but stepped away from FE work when flexbox and such were really coming out? Any sort of "catch up on the last 5-10ish years of CSS changes and how to think about them" sorts of resources?

Thank you!