Solid studies and good progress.
You mentioned shading twice, so I figured I would mention something that might help. Might not. I'm not an art teacher, but it's in my blood.
Shading follows your knowledge of the underlying forms and good understanding of lighting. If you have the time and want to crack into this early, do some still life studies and really observe how the light falls across the surface of different fruits (apples, bananas, etc) and how distance of the light impacts it. If you have (or have the means to acquire) a set of geometric solids (sphere, cube, cone, cylinder, etc.), do the same with those. At this point you should be aware that every complex object can be broken down into simple forms and your study of these will provide a solid foundation of shading moving forward.
Term 4 Week 1 (where I am right now) has studies with shadowcasting, but it is a fairly technical approach involving perspective. So that will be appropriate in understanding how to light/shade you 3pt perspective gate. For portraits, you might want to do some quick studies where you are just doing shading across the different surfaces without worry too much about details. To see the shadows better on references, just squint your eyes. There is something else on shadows in general this week as well.
EDIT: Here's a video that was just released on YT today that seems like it might help too.
