I looks like you have all of the important muscles in your drawings, now it's just a matter of figuring out where they connect and how they change when flexed. It's a truly wonderful challenge to take on :) What helps me is to do tracings before I dive into an anatomical study. I find that I ask more questions when trying to work out what goes where beforehand than when I am in the midst of a drawing. You could print out the images and use tracing paper or do the tracings digitally. It also helps me to label the muscles. That's just what works for me, but it could work for you too! I also try to find references to have available, like Richer's Artistic Anatomy and the free app 3D Anatomy for Artists, which is a great way to learn the origins and insertions. I included my tracing of the images you included. Hope that helps!

Looking good! There’s a piece of the scapulae that you can actually see from the front. It’s something that surprised me when I first learned about it. Hope this helps! Keep up the anatomy tracings! You will learn so much.

These are lookin pretty good! Double check your proportions of the middle portrait. I think you foreshortened the head a bit too much, and the neck is a bit short. Check and measure your negative space around the head and neck areas for both the references you have posted here. You'll start to see where you can make corrections. Keep it up!

Looking good! Be mindful of the connection point of the spine and the pelvis, it should be towards the back edge of the bucket.

Hey nicely done great exercise! I think I break up the fat pads a little differently that what I'm seeing in these drawings but the fat pads do vary quite a bit from person to person and simplifying them into generalizations can be done in many ways. You might try adding them onto a skull with clay for this exercise. Keep it up!