I DONT KNOW how to get to know him better?

You need more confidence, this guy is new, of course he would want to hang out with someone , anyone, and this Crystal girl is no competition, like honestly she had to get the teacher to help her hang out with him, where as you could just go up to him and invite him to hang out after school. Be friends with him first, believe me if he is alone here, he would want to hang out with locals!