So I wanna talk about this.

And first I wanna talk about the mouth, because there are the roots of some really bad habits there. One thing that sticks out at me above all else is that, well, you've got the beginnings of the flounderface.
What's the flounderface? The flounderface is a mistake commonly made in amateur illustrative art when it's trying to emulate an anime style, where the mouth in a character profile will migrate inwards -- giving the appearance that the mouth is actually stuck onto the side of the face.
Thing is,
this does not happen, either in real life or in professional illustration. It's something you see in anime quite often, but here's the thing:
it's an animation shortcut. By moving the mouth inwards, you make it easier for the animation team to draw frames for speech without worrying about things like lips.
That's it. It has no reason to exist outside of cheap animation. Doing it in an illustrative piece is both very obvious and very
wrong to a viewer. It might work for now, but you're going to find yourself very limited in terms of expressions if you only ever think of the mouth as a small black line and not the empty space between two lips.
It really can't be overstated how necessary it is to know structure and anatomy before you begin stylizing your work. Manga-style might seem superficially simple, but
unless you know at least the basic shapes that compose the human body you're going to be restrained to a few "stock" poses and angles, and remain incapable of any real dynamic posing or action (or even things like close-ups and reaction shots).
It's a long, hard road, and there's no doubt about that. The benefits are immense, though -- there's no describing the satisfaction of a piece coming together the way you envision it.