I'm a noob, I've been looking at the 18-Standard cell GDSII with KLayout. There are 15 layers on the cells I've been looking at with designators such as 64/20...to 125/44. Is there a cheat sheet floating around that describes these layers such as MetalConnect, NMos Substrate, P-Well...etc..

Install this: https://github.com/laurentc2/SKY130_for_KLayout