I mean, you're on fediverse.boo, and I'm on kbin.social, and I saw your comment here, and am replying to it. I'm pretty new here myself, but I'm finding no issue discovering communities on other instances and subscribing to them to have them show up in my feed. So I'd say subscribe to the communities you want to contribute to, and post. I'm sure we'll all be able to see it and interact with it.