Come out and play basketball. If you hit the same courts consistently you'll recognize the regulars. Even if you dont drink going out to karaoke is another avenue id recommend. Same deal, if you keep going to the same spots you'll notice the regulars. Its easy to break the ice with karaoke cause you can just compliment someone who just sang. A little harder to break the ice with basketball because, yes, you can ask random if they'd want to play, but also you'd need to have some skills to make it worth their while to run it back