Does he have friends that will play? A lot of wargaming is just garage folks. That requires a group of people you can play with regularly. Kinda sucks to get into a game and you have no one to play with.
Go to your local game stores that do wargaming and see what the scene is. Plural stores is important here. The store with the biggest scene might actually be the worst to play at or host the dumbest players. In my experience, there are shops that have lots of models and accessories with huge play areas and there are shops with great scenes geared for all players. Sometimes those intersect; often they do not. You’re looking for a friendly place willing to cater to beginners. Good starter scenes have lots of people willing to share armies so you can see what’s going on.
How much do you want to spent right now? Kill Team, Combat Patrol, full 40k in that order is probably cheapest. AoS doesn’t have the cheaper options yet AFAIK officially but there are some smaller skirmish options.
Marvel Crisis Protocol and Star Wars several things might be better options based on the first three points depending on your wallet and local scene.
However, in my experience, once you start one of these things you usually dabble in lots especially if you’re at a good store.
However, in my experience, once you start one of these things you usually dabble in lots especially if you’re at a good store.