Routines for youngins

Hey guys…my cousin recently turned 14, and he wants to start working out. He’s a little overweight, etc, and I really want to help him look better, feel better, perform better on the field, and just be more confident overall. I told him I’d help him, but I really don’t know any routines that would be suitable for someone his age. I’d prefer to focus on muscle building over fat loss, as I think he’ll start to shed some babyfat as he matures. If anyone can make any suggestions it would be great. I really appreciate the help, everyone. Thanks in advance.

Standard compound movements at a medium weight and higher reps. Focus on form first. GPP would be good as well.