Check out fencing. Local fencing club has classes for kids and adults all ages. They also do birthday parties, so that might be something different that would be fun for him and his friends.
If you’re ever in a situation where you’re worried you might need people to believe you in the future, take contemporaneous notes. Write or record what happened, how you responded. Focus on the facts but don’t ignore your thoughts or feelings, include them in your notes. Date and sign it. Keep it safe.
The thing about behavior is that if you practice you get better. That goes for good behavior and bad behavior. The more you lie, cheat, etc. the better u get. Decide What kind of behavior you want to be good at and then practice practice
Be yourself. No need to pretend to like something the crowd is doing. Half of them are probably just as unenthused as you are but are afraid to say so.
Keep stories about younger years to tell them later: You used to call yellow “lellow” etc. Ten years from now you think you’ll remember this stuff but you won’t.
Here’s the thing: some whacky $@!#% is about to go down. The next few years will be interesting, awesome and awful all at once. We will rely on kind and respectful communication, have as much fun as we can, forgive often, learn to let go and trust, and learn to be trustworthy. If necessary we will seek the advice of experts and the counsel of loved ones. Shifts can happen fast, for the better or worse. It seems like the end of the world but it’s not. You’re stronger and braver than you know.
There is an expression “God only gives you what you can handle.” I think that’s backwards. I think that God gives you the grace you need to handle whatever comes your way. He is faithful and generous. I think that’s what “Be not afraid” means.