I would say try to get to know him, get to know his strengths and weaknesses, his likes and dislikes. Teasing can be good if it’s not about something he’s sensitive about and you make it obvious you’re teasing him. Definitely try to give him support. As Wiz said, show him you care about him.
That’s stuff I’d say as a boy, but everybody’s different so I can’t really give you a perfect answer that fits him because I some know him. But I think that stuff should be good, someone can correct me if I’m wrong.