If you want to use glBegin() / glEnd() - like immediate API with modern OpenGL, I reecommend using a library called RLGL (https://github.com/raysan5/raylib/blob/master/src/rlgl.h), from Raylib. You'll feel straight at home!

Same sentiment here. My litmus test is - after creating a window - "how many lines of code does it take to render a triangle?".

With the old OpenGL API you could do this in like 10 lines of code (probably even less with SGI's GL).

With the new/shader-based API, well... https://learnopengl.com/Getting-started/Hello-Triangle

Vulkan - I don't even want to know.