Since he is new, I would be as friendly as possible. Don't scare him off by telling him right away you like him. He is probably shy and feels out of place b/c he is new at school. He wants to meet new people, and approaching him like you would any of your friends will make him feel more comfortable, welcomed. Ask him if he wants to hang out, or show him the ropes of your high school. If you gain a new friend, great. If you gain a boyfriend, fantastic! Just don't push it too fast.