Anatomy first try

First time practicing anatomy, specifically the torso. Very rough sketches, I know. I'm using Draw Like a Mangaka by Marcel Kühn as reference for learning anatomy and wanted to know if it seemed like these sketches were a step in the right direction even if it looks very rough at best. Also if anyone has suggestions for anatomy learning resources, books especially, would be greatly appreciated.

Digital drawings on phone in Ibis Paint X. Looking for feedback to know if this is a good first step.