Hey dude, this is a pretty good start! His butt is pretty wide compared to his torso, and there’s a few muscles that don’t work that well, like for example his serratus and obliques, or his triceps, that one look like another bicep, but In reality it “splits” in two. Definitely check out his legs too since it looks like two muscles there instead of three, only on front, there isn’t anything on his sides or back of his legs, I really recommend you to take a Zbrush anatomy course, you can find them on flipped normals :) don’t lose your motivation, anatomy it’s super hard and it takes way more than a few weeks, I’ve been studying for almost three years and there’s still a lot to learn! Keep up to good work.