A booth is a small room, a very small room. Shop can mean a room also, as in a workshop, the tool shop (where they have drills, lathes, welders, benches, etc).
On the streets (before mobile phones) we had telephone booths. Apparently Superman and Dr Who still need them )))
Another booth might be a small one-person shop/room in the shopping centre, where they do clothing alterations, key cutting, and small repair, but it is not a big shop; it is a small booth or workshop.
A room is a place in a building. Eg. the kitchen is a room (or it could be at one edge of a lounge room), a bed room, a bath room, the toilet is a small room. The laundry could be in a room. In Russia, the laundry was in the bathroom.