Dude, for a beginner that fucking stunning [pardon my french]
Lines are a slight bit blocky, but the turnout fits..
Try using some different coloring methods..
I think you did a great job..
Keep up the good work and be sure to practice ^-^
You should use gradients and blending for vectors too, it helps keep along the same lines as the original and makes the image look better overall, you should zoom in to around 800% when doing your vector and take your time more.. it takes lots of practice but the feeling you have after is great.
Try to work on your eyes and mouth a little, and maybe even move onto shadows