Yo muh boi, Nymia whats up, I'm new here as well.
Haha yeah drawing on glass can be frustrating. If you want to reduce that slippery glass feel you can get a matte screen protector for whatever drawing tablet you use. The Paperlike one is pretty good if you have an iPad.
From my understanding of what Marc said in the figure drawing video for these exercises, it looks looks like you're doing exactly what you're supposed too:
Line of action,
head, rib cage, and pelvis regions
ball joints and connecting lines.
Good work on estimating where those joints are that go behind the figure. You're well on your way with your art journey.