@turbobureaucrat

Gup.pe groups can be created by anyone, so feel free to start one if there's a topic you're passionate about.

You can also follow hashtags. Those are a bit less reliable, because you'll only see the posts that your instance knows about. On the other hand, more people use hashtags than groups.
(Talk to your admin about relays if a hashtag feels too quiet)

Finally - you can send your question to the # AskFedi hashtag, or check out https://fedi.tips for more info on how to use the fediverse :)