Most tours allow spectators and have specific rules about them. Cart use, behavior, attire, and contact with players is usually very specifically defined in the tour rules. Spectator carts are invariable restricted to the cart path only. To rent a cart, you go into the pro shop, pay a rental fee, and get a slip. You then take that slip out to a cart attendant and he will give you a cart to use. I’ve never seen a course allow more than one person per seat, which in most golf carts would be two people per cart. Some courses have a loose policy with regard to kids and we often see mom with two siblings in a cart, but pay close attention to the rules, as your golfer may be penalized for rules violations by their spectators. Also pay attention to the tournament rules regarding the players riding. Sometimes riding in between holes is allowed for the young ones, but most often they must walk.
Be sure to keep interaction between spectators and your golfer restricted to nutrition, well-being, or encouragement, and double check with the tour director/rules about that. Most kids golf tournaments allow the golfer to get a drink or snack, sun protection, or an “at-a-girl” from their spectators, who are most likely family. Don’t forget players usually can’t ride.
Remind your spectators that quiet talking is okay of course, but when any player addresses the ball, silence is required.
I think spectators are good training for the young golfer. A little added pressure is very realistic as they grow with competitive golf. Good times for the spectators too!