Well, for ur first drawing… great!
Usually u would use a flat color for hair base then go over it in a lighter color with a brush like round brush point. For the face, try using a full continuous line. Add a line thru the middle to find the correct position for the eyes, u can find the nose/lips from there 
use a reference to help w anatomy. Maybe try drawing over episode characters to help w positions of features (: hope this helps u!