Allan,
I am in a similar boat to you; no hobby clubs nearby......
So this has become my 'digital' club.
Colour theory, or light and shading? Similar ideas, slightly different interpretations.
What I have gleaned from here;
Highlight reds with orange or yellow, rather then straight white
Shades for red, I use magenta.....
Grab a figure that is only for practice, and experiment.
From the red shading learning above, I now try and steer clear of using black and white for tonal differences. That's just me, you'll find your own system that works for you.
Keep sharing as you go, good to see your efforts
Cheers