I would first try to get the lineart right and then shade it.. Here are some things that are very noticeable in your piece:
-Eyes have a very strange shape.
-Nose has shading on the left side, while thats the side where the light comes from.
-Head is slightly strange shaped. It should be higher since the eyes should be approximately on the half of the face.
-Usually the area above the eyes is shaded if the light source is above the head, since the area around the eyes is concave.
-Why are there rings around is neck?
If you asking yourself how to fix those mentioned things exactly, I would suggest taking a reference picture, that will help you a lot in fixing anatomical things.
Looking forward to see your progress on this one
