Where can i read about the implications of a fourth spatial dimension in layman's terms without just being given "the fourth dimension is time!!!" stuff that goes on to talk about time travel rather than weird shapes?

I am mostly interested in the hypothetical sense, like whether a 4D observer could see every point on a 3D object like how we can see every point on a 2D object, or in trying to explain how we'd perceive 4d objects, not so much on details like "Well we know there's no 4D observer because the existence of a full fourth spatial dimension would go against our understanding of physics!"