What should I do, exactly?

Okay, so there's this guy I really like and he really likes me. I'm only 14, though. He's really sweet and everybody knows him as Mr. Nice Guy. He's captain of the basketball team and good-looking, too. It's just that I really don't wanna become an infatuated, annoying teenager. -- I'm also a tad bit afraid of getting hurt. What should I do, exactly? :(