Find and work through some old OpenGL tutorials from the fixed-function era. It's long obsolete, but there's a nice immediate connection between your matrix al

Find and work through some old OpenGL tutorials from the fixed-function era. It's long obsolete, but there's a nice immediate connection between your matrix algebra and what you see on the screen. Putting chunky triangles on the screen is fun! Edit: I should mention that this is a good way to learn to appreciate what modern shaders are doing. You could jump into those as well, but I think it's a little harder to get your first triangle on the screen. All this assumes you're comfortable writing C, of course.