What do you do when you like a boy but they don't like you back?

The best thing to do is to try and be his friend, get to know him and let him get to know you. But be careful not to get stuck in the "friend zone". The best thing to do is be yourself and make him laugh. Be his friend. If he really isn't interested, it would probably be best to let it lie. Don't pursue it if it won't happen. Good luck!