Welcome to our community... we are a friendly (though, sometimes a bit heated to each other) group, that truly loves the art of printing and running businesses, and helping other to be successful.
one thing I'd like to mention, just so you don't get discouraged... it's hard for many of us to have unpaid help in our shops due to insurance regs, department of labor regs, and just the lost productivity of trying to teach someone from the ground up. These days if we have an intern producing work that makes us a profit, we have to pay them.
you may want to look into taking a class (if you can afford the expense of going to washington DC for a week and the cost of the class, the Totally T-Shirts class offered by SGIA is an awesome way to experience EVERYTHING it takes to be a screen printer, from producing print friendly art, to preparing screens, to printing, to multicolor, cleanup, special effects, etc).
There's other classes offered around the country as well.
Any of those would make you a good candidate if you're willing to work for a low $$$ amount to truly learn the craft, or REALLY set you up well for doing stuff out of your house.... a beginner screen-printing setup can be put together for a few hundred $$$, and you'd be miles ahead of doing the printing with the freezer paper method...
One other word of advice on the art side, is try to create some single color jobs at first and keep in mind the graphics elements that stand out, without making the art too hard to print. Corporate "artists" are the worst at this, generating stuff with lots of gradients, fills, colors, etc, which makes printing their jobs costly... Doing some very clean, fun 1 color stuff is a good challenge, and then making the screens to match that.
