It depends on the kind of game he wants to make.

If it's about 3D scenery or physics, I would recommend Godot. Just import some 3D models, place them into a scene, add lights and physics, and you need very little coding to have a simple 3D game. You can add complex logic and UI later on.

If the focus lies on UI, NPCs, combat, or inventory, I would recommend GameMaker instead. It's 2D, but it's made for that kind of stuff.