https://joinmobilizon.org/

Maybe you can also find open source communities in your area. After some digging, I was surprised how many groups there are in my area and they are always happy to get additional hands to organize stuff or run errands etc.

Sure it’s allowed, but we have these questions a lot, so some enthusiasts made some really great posts with tons of info, for example:

https://lemmy.ml/post/12123645

https://lemmy.ml/post/18268622

I’d recommend to read through them, then come back and ask more specific questions.