Hi Jeff,
Very nice drawings, and you're definitely on the noble path, building a foundation of skills before you throw color into the mix.
Something I am revisiting in my own work - think about representing a full range of values in your work. Early in the drawing find the lightest light and the darkest dark, and then compare every other value you see to those bookends. I think that will really help you to develop solid, 3-dimensional form. Go
here and
here for great descriptions of the importance of a clear 3-value scheme.
This Forum is really developing into an educational resource; it's very frustrating trying to learn how to paint/draw in a vacuum.
It sounds like you have an "open studio" session that you can attend, and I like how you grabbed a mirror when no one else was available!