I did a quick draw over of this face to point out a few things that might be helpful. The eye on the far side looks like its placed higher on the head than the one the near side. And from the angle we're looking the bottom of the eyelid should flatten out. The mouth and nose are in the right place but they look a bit too flat, making the far sides on both shorter or more obscured will help create a rounded feeling to the face.
All that being said your proportions look good and that's a very solid start. Your perspective and figures are also off to a solid start, I look forward to seeing what you do in future assignments