Just start. You don't need guidance, you don't need permission. Get a book on graphics, read it, and then implement a few graphics related things. If you don't have access to good books, find some tutorials online.

Get a 3D cube spinning on the screen, using OpenGL, DirectX, or software rasterization; raytracing a chrome sphere on a checkerboard infinite plane; implement and optimize Bresenham's line/circle algorithms; write a voxel engine like Minecraft or Outcast; write a DOOM-like raycasting engine.