How well do you know him? If you know him a little, walk up to him, smile and say something non-commital. You can compliment him on his clothing, ask him a question about a school activity or a class, see if he has any suggesstions regarding what movie you should see or restaruant you so go to for dinner, ask him if he has any vacation plans for the summer, etc.

If you do not know him, approach him, extend your hand for a shake and introduce yourself. Then, start a conversation. He may be just as anxious to meet you.

Whatever you do, good luck. Let us know how it goes.