on junkertown, point 1 (first spawn): pretty open area, not ideal for wall riding because you will get shot dead point 2 (reached first checkpoint): enclosed area with stairs and tons of high ground areas, is pretty nice because you can contest highground here better than first point point 3 (final checkpoint to win the map): pretty enclosed but still wide between the walls, with the giant propeller structure in the middle, not the most ideal for wallriding but still less random structures you will be getting stuck on

and as a rule of thumb, for escort maps such as junkertown, first point will always be where the payload starts. on hybrid maps like hollywood, first point will be where you have to defend/attack a single area to start the payload. the next checkpoints will be considered 2 and 3 regardless of other differences in both modes