Specifically I'd suggest sticking to OpenGL 4.x and ES 3.x when learning OpenGL. Even OpenGL 4.4+ brought a lot of changes that should be used instead of what e

Specifically I'd suggest sticking to OpenGL 4.x and ES 3.x when learning OpenGL. Even OpenGL 4.4+ brought a lot of changes that should be used instead of what existed before (bindless resources, texture/buffer storage, persistently mapped buffers, etc.)