Ok, so I'm making a game primer. I'm using Cocoa and OpenGL, and I want to figure out how to make the level class. ??? I really am confused about how to do it, before I have always made board type games where it was a simple matix array, but now I dont know, plz help...

This really depends a lot on what you want your levels to be like. A level for a flight sim would be represented differently than a level for a block puzzle game or a platformer. Perhaps if you tell us more about your game we could point you in the right direction.