Martial arts, acting classes, art classes, church groups, tennis, racket ball, pool, table tennis, your local YMCA or Boys & Girls Clubs may have programs your kid would fit into nicely. I may steer away from group sports activities because he is 10 and many of the group sports boys may have been at this since they were 6 and many may have friendships already developed.
The martial arts may help with his esteem giving him confidence with defending himself from other boys. Boys tend to be very physical with the hitting, pushing, shoving and wrestling. I hope this helps.