What should I do with this relationship?

I have been dating a guy for over a month... but we've only been on one date. He just went on a month-long vacation with his family. I'm about to be a high school junior; he's about to be a college freshman. And he's going to a college six hours away. I like him, but I'm not crazy in love with him, ya know? It seems that he likes me more than I like him. He's leaving for college in about a month. How and when do I end it?!