Yeah communities are a ghost town, but they do have a handy tag at the top of the post to tell you where the note has come from, similar to followed hashtags (on amethyst at least).

I just feel so out of my depth with relays lol. Say you are following 20 topics, you would have 20 relays? How would I post to just one relay? Maybe it would be similar to posting on a community on Nostrudel, where you select from a drop-down menu? But yeah the difference being it wouldnt also post on your main feed? I have no idea lol