I wanted to know -

Does shark skin feel like dolphin skin feels and does that feel like whale skin?

Are they all the same sort of thing and how are they similar and different? And is there a reason why since they all live in the water anyway?

(Sharks don't have scales like fish either, do they? - sorry if I am being dumb)

Sharks do have scales, but they are bit different from fish scales. Shark scales are anatomically similar to teeth (they are made of bone and have an interior pulp with its own blood supply). Whale and dolphin skin probably feels a lot like human skin since they are both mammals. Shark skin feels different depending on how you touch it. If you move your hand from head to tail, it is very smooth, but if you move your hand towards the head, it feels rough. This is because a shark's scales are layered on top of one another, kind of like roof tiles with the free ends all pointed towards the animal's tail.