He probably would not be able to work a regular part time job like at a restaurant or retail. The schedule may not work out for him. Most of those jobs require people to work weekends or they would schedule him during practice hours. I do know kids that would ref men's league games at night to make a few extra bucks. I also know kids that did something like Uber Eats. I would say that a job where he can make his own hours like Uber Eats or something where he can pick the nights and times to work like reffing would the best option. He won't get rich, but doing things like that would certainly cover spending money.