Earning money by selling artwork is harder than mowing lawns, babysitting or bagging groceries, so consider getting a regular job first if you need money. If you are determined to sell art, it would still be a good idea to get a part time job while you learn to market yourself properly.
Here are some tips about finding freelance work and pricing: [link]
If you're going to run a small business to earn money you should figure out what you need to do in order to not get in trouble with your local authorities and tax people. This can be a lot more complicated than "buy my stuff!" and might actually end up losing you money.
Er... if you don't know this stuff then trying to run an art business (and that's what it is, it's a home-based business) could get you in a shitload of trouble. You may be responsible for collecting sales taxes, if you ship stuff you need to think about customs fees, and so on and so on and so on. If you're a minor (I don't know if you are or aren't) then your parents might be on the hook for all this stuff.
Oh, I'm well aware of that. I know I'd have to pay certain fees to pay for shipment of anything I mail out. That's a given. As for the sales tax I will look further into it. I was initially going to do some research into art commissioning but at this point I really just would like to test the waters first and see if others would be interested in buying my art first. I think before I progress any further with this I should do a test run first. And if it turns out to be a pretty good route then I will take all the necessary means to start officially selling my art work.
To get your art out there more, you need to submit more, and hit all your groups with your art.
However, DA is the worst place to try to sell art. Art sells best in person. From the little I have seen at your gallery, looks like you lean toward anime, which will mostly sell at anime-con's.
For selling any art, your best bet is fnding your target audience, and marketing to them. For example, if you did fabulous, lifelike drawings of horses, you should get a table at horse shows, and go other places that people with horses hung out.