Welcome! FYI, telling us where in the world you are is helpful in so many ways.
Like others, we ran an SC2 for number of years and most of its failures were caused by us.
When prep'ing the car, remember this is a marathon that is run in all weather so:
Remove all the interior with one exception. This includes the annoying sound deadening in the floors.
Figure out how to mount your seat, even temporarily, before sending your car off for cage (you indicated you have no fab skills so do have it professionally done).
Leave all wiring harnesses intact...your new, this is not the place to save weight or complexity. For instance, in the early generations there is an oil pressure ignition kill circuit some teams have accidentally disabled.
Use the stock gauge cluster (see above on wiring).
Replace known failure items like the Crank position sensor, alternator, starter prior to first race and keep the originals as "known good" spares.
Consider the same of the coil packs but we tended to just get junk yard spares and run them in test and tune to mark them as also known good.
Inspect every millimeter of the hard brake lines, particularly the rear lines from the back of the doors rearward...they rust...a lot and this is a difficult repair at the track for most.
Get a pair of front knuckles and put new bearings in them...Front wheel bearing suffer failures often and this is a really tough fix at the track so swapping in spare knuckles is better...I think we were down to about 15 minutes to do the swap at one point.
Consider buying new axles at a chain store on Thursday and returning them Monday if not needed. It is of the utmost importance that you open the box and inspect the axle before leaving the store...all three chain stores in our area where getting their rebuilts from the same supplier and they were putting passenger axles in the boxes for drivers axles.
Gut the filler neck and remove the anti-siphon ball.
Baffle the oil pan IF you have the engine or transmission out of the car. No fab skills to do it yourself...let me know, a partner team might still have our old baffled pan from our former car.
Remove the stock cimate control...at least leave the blower/heater core and defrost duct...you can wire it to just a 20 amp switch but honestly, the head does not take up much space.
Remove the windshield wipers or their controls.
Go down a rabbit hole of "Making it better". One exception is potentially swapping to rear disc just for ease of track maintenance. These are competative B cars out of the box and first couple of races, you are unlikely to be a competative team of racers.
Modify the front facia of the car without serious consideration to airflow through the radiator.
Some parts are getting harder to find like spare manual transmissions...the diff pin can back out and trash the tranny but disassmbly, welding up the pin and reassembly is not a simple process. Long term...it is important but just having a spare is a good interim option.
Without a doubt the best way to secure spares is to buy the same gen sedan (normally $7-900 here with significant body damage or a phantom no-start condition), remove the whole front subframe and carry that for spares...it is a tidy package and includes everything but rear brakes, suspension and hubs that can reasonably fail at a race. It is light enough that a team of 4 can lift into your truck bed or onto your trailer without a hernia.
Always keep in mind KISS. The teams that have the most fun and do the best spend their time on track...not fixing things (OK, some like fixing things) so never complicate something for the sake of making it better. Trust me, you are not making it better.