He should do something that will help him out in the trade he wants to do. If he wants to be a mechanic have him apply for a mechanic shop, electrician have him pull wire for one of the electricians. Lehi is a hot bed for construction with the growth.
UPS wouldn’t be a bad career choice. You always be in shape and the pay is pretty great especially for not needing a degree. I did the mission and then college route so I had a few years to decide on what I wanted to do after high school. Having a job is important but it sounds like he needs to find one that will help in his career.