Good for you man, I remember when I was your age (almost 20 years ago) and doing similar stuff on my cars. It's a great way to learn with hands-on experience and trial and error.
So there is no muffler anymore, it must be loud I am guessing. What size piping did you use? Looks to be maybe 2.75" OD? You'll actually be surprised that going with bigger piping on these cars for exhaust can make less hp on the dyno. If you go with 2 3/8" or 2.5" OD you might see a little gain in tq/hp. Also just a side note, that when you eliminate the muffler it actually affects the rear diffuser/under aero of the car. The stock muffler was designed to flow air through the rear diffuser. Now that you don't have a muffler, there is a large area under the bumper there that acts like a parachute and will actually create rear-lift at higher speeds, which can unsettle the rear on the track/canyons. You can maybe undertake a new project though for your class and fabricate a piece of sheet metal from the differential to the diffuser so that it directs to air properly again
Something like this...
Also, looks to be mild-steel piping? If that's the case, some Jet hot paint for exhausts will protect it from rust, or you could ceramic coat everything, otherwise you might see everything starting to rust in a couple months...