More importantly I would suggest the Arduino, it can interact with Processing and allows you to control physical objects with your code. Carlos Amorales, the mexican artist, works primarily in digital forms, but only sells his work printed intaglio; the art world still prizes physical originals. Hopefully this isn’t a disappointment to you.
If you’re willing to use your code as part of an installation, you’ll have much more success than just trying to sell the digital files. I’m an experienced lithographer, and can give some advice if you’re interested in printing your creations. (Remember, physical originals.)
But, remember. You’re a sophomore and thinking of your future, that’s amazingly precocious (in the best way). Don’t get too worried yet!