I suppose this question has been asked thousands of time on the forum but I ask it anyway:
I want to start creating a nice and clean 2D game, not too simple but not complex either. I'm not an expert programmer yet...
What are the pros and cons of SDL, GLFW and SFML?
I personally use GLFW, but AFAIK SDL is easier to learn.
If you just want to write a game, not an engine, I recommend LÖVE.