I think they're pretty good for a beginner my advice for the first picture would be to add a bit more of a hairline above the fringe, or just bring the fringe a bit lower down, as most fringes reach the eyebrows, as you generally see more hair on the top of a head. Also, the white circles for sparkle/reflection I think might be a bit big, it makes the eyes look a bit busy - though it might even out if the pupils were coloured.
The profile is also pretty good I would suggest making the ears slightly bigger / move them down a bit - if you feel your own ears, the bottom starts around the bottom of the mouth, and the top is just below the eye. You could also add a slight curve to the forehead (not too big) so it doesnt look completely flat. And the last doodle is super cute I love that apple. Hope it helps and doesnt sound harsh or anything! Would like to see more pics!