I believe that the concept you're thinking of is "ambient lighting". I'll defer to better artists on whether that's possible in this setting and how it might best be applied.
Also, not to minimize how pricey art can be, there are good tablets on the cheaper end of the spectrum that will still get the job done if you prefer more general digital art over pixelling. Wacom came out with a new line of Intuos pen tablets, you can get the
Intuos Pen Small for $79.99. On Amazon you can also find their old line
Wacom Bamboo Capture, pretty much just as good for $65.99. Not as cheap as a pack of pencils and a notepad, but it might be worth saving up for if you're interested in that sort of thing. I've had my Bamboo for a few years now, and it works great for sketching and painting alike.
I look forward to seeing you on here!
