Does Ursina allow for one to create an invisible barrier to prevent the player from falling off the map, if so, how could I do that, if not should I just add walls to prevent that from happening?
Yes, it is possible. You can create an entity and make it visible = False or just make it transparent (less optimized) color = color.rgba(0,0,0,0)
Here is an example:
barrier = Entity(model='cube', collider='box', visible=False)