Hi, I'm still a newbie myself, however, allow me to give you some crituque:
I've pored over your three images, I think structurally they look impressive for a beginner. However, you are focusing far too much on contours and shapes in your gestures and less time on the actual GESTURE of the figure. That is to say, you are mainly concerned with the drawing looking like a completed image rather than worrying about how you're translating movement on page.
You can start by observing your lines: they lack confidence. I can see by your strokes that you are more afraid of messing up than making mistakes, and that's normal. Try to draw more confidently by practicing ghosting your lines first on a separate paper. This will teach you a bit about line confidence.
Next, your boxy figures are good, however, you're relying on them too much. Scribble, loosen up a bit and draw what you see the gesture doing and not what it is. I suggest starting off by doing simple lines.
I hope I helped.
