I personally only have experience with the SFML library. It's a pretty intuitive system for 2D games but I haven't really looked into its 3D capabilities. I've also heard good things about GLFW, which is what I plan on learning next.
SFML makes setting up windows easy and provides a bunch of classes that can be drawn to those windows, such as sprites and rectangles. The general structure is a loop that updates and draws these objects to the window buffer and then displaying the updated buffer to the window. I'd highly recommend checking it out if you haven't learned anything about graphics libraries yet, it's a good starting point.