Or are you like me and (for the most part) don’t?
I have one community which is on Discord I take part in on occasion. It’s nice with the occasional fandom event, like my upcoming rarepair week. Yet I don’t have a lot of places where I can talk about my preferences for my fandoms outside of the comments on my fics.
I mostly engage through fanworks (commenting and replying, though I am sometimes super late with my replies). I don’t frequent any specific fan space, but I will get into discussions with friends who share the same story interests. Even if we differ in terms of our HCs, it can be fun to discuss the broader story, how the creators convey things and the various aspects we enjoy or find troubling.
I actually love it when people just toss ideas out there and say “I would love to see someone run with this” because so often I’ll stumble upon fanworks that my brain would love to expand on, but I never would because it would feel like stealing someone’s ideas. It can’t hurt to generate a wish list for content. You never know!