What kind of activities could they do that would appeal to you (and other young people like you)?
I recently got divorced and I'm sleeping around a bit. The social groups for sleeping around are rarely called churches. There's no Satanic Temple around here or I'd try visiting them.
I saw that "Sacred Harp" a capella style posted here on HN a few weeks ago and it captured my interest. I like the idea that I wouldn't have to be a great singer, I could just be part of a bunch of people doing something for the sake of fun. But even the UU hymns feel too saccharine for me already.