Should I make a move on him, or wait? And does he seem like he likes me?

If you haven't talked to him face to face, you should do that. Just to see if he really is into you, or if he's just being friendly. Chances are, talking to him will make him think that you like him (if he likes you) or make him think you just want to be friends (if he doesn't like you.) so either way, talking to him in person is he best thing to do. Just go up to him and say something like, "I overheard what you were sayin about _____ and I think _____" or just go say hi. But if he's with his friends, bring your friends to make it less awkward.