Start with a meetup you are interested in - sports team, coding meetup, community event, etc., and identify the most interesting people there by just talking to a lot of folks. Build some rapport, figure out what else they do for fun, and then see if you can also join in. You'll likely end up at a number of events that are a dead end, but with enough cycles of this you can narrow in on communities that work for you.
“Interesting” doesn’t describe a property of people. It describes how you react to and feel about them.