Hey, welcome to CA It's never too late to start painting and drawing, so don't worry!
I love the studies you've done so far. If you feel something is really weak (a body part, gesture, whatever), just do studies of that thing and you'll get better with time.
Don't be afraid of colour theory! I had some of it at school (for graphic design and printing, though, not painting... it's a bit different) and to be honest, I think you can learn as much (if not more!) by just carefully observing and doing studies
If you're not sure if you're going to like digital art, why not borrow a tablet from someone who has it? It's not that different... most people just have a problem with sitting in front of a computer for a long time.