That being said, the vehicle came stock with a CAI. Its stock exhaust is also suitably sized. They will gain you little. You could port the heads and run larger valves, those should pick up a little. Don't expect miracles though, it would outrun any stock 2.3L N/A at that point, but is still not going to be fast. You can get a different cam and that will make a big difference.
If you are broke college kid, as you claim, you should not worry about getting more performance, reliability is far more important than performance when you are on a budget. The old adage holds true for this, if you want cheap and fast, it won't be reliable, if you want cheap and reliable, it won't be fast, if you fast and reliable, it won't be cheap.
There are virtually no easy cheap bolt on parts that pick up significant gains over stock on most engines, the Ford 2.3L are no exception. If you want to get to any reasonably power level, you need to spend money.
The best bang for the buck, the most performance for dollar for your setup, is to swap in a Ford 2.#L turbo out of an SVO, Turbocoupe, or Merkur. This will step the power to between 150 - 190 hp in stock form, more than double what you have now. Obviously this option isn't cheap, but it is cheaper for what you get than a CAI ($50 - $300 depending on complexity) or a full exhaust ($75 - $500 depending on size, complexity, muffler choices, cat choices, etc.) i.e up to $800 to gain you an optimistic 10 hp. You could buy a turbo motor and the immediately related parts complete with VAM and computer ($250 - $1800) and gain as much as 102 hp. With a few more simple mods, like a manual boost controller, a proper intercooler, and larger exhaust, and you can get that to around 250 hp. Again though, obviously not cheap, you are still into it a bit at that point.
Again, if you really are a broke college kid, save your money, focus on school. Then get a good job with your education, and then use that money to pay off student loans and buy nicer things. Don't try to mess with things like getting more power out of a car while your funds are tight.