How to become best friends with my crush?

K so there's this guy I really, really like. I talked to him quite a bit before I started to REALLY like him. He isn't in any of my cles though. And he takes my bus sometimes but he's usually with his older brother or sister and I don't want to talk to him when they're around. And even if he is alone what do I say to him? I dont know how to start a conversation with him. And if it helps I'm really, really close with all of his friends. I want him to be my best (guy) friend! Like I can just go up and say anything to him! Oh and should I compliment him or something? Do guys like that? Oh and also I went to Tim Hortons with him and his friend once...Sorry my question makes no sense but I really hope you can help me!!