Basically none. A couple friends have learned a little bit with me, and I’ve sought out a couple Esperanto books, podcasts, etc. But otherwise I can’t say that I’ve ever randomly run into another esperantist I could talk to, and I’m not the type of person who sucks out clubs and conventions or making friends with strangers online. But it’s an easy language to learn, and I feel like it’s taught me how to learn a language, and I think that I’ll be better prepared if I ever decide to try picking up another language somewhere down the line. And while I’m not holding my breath, I like the idea of an international auxiliary language, and while there’s some valid criticism of Esperanto for that purpose (like that it’s too eurocentric) it’s probably about the best option that we have right now since it already exists, there’s people who actually speak it and it doesn’t have all of the weird grammar rules and such that natural languages all tend to have.