^^^Depends on what class you are already in. Going from a 215 to a 225 won't have any real effect, not as much as just playing with tire pressures will be. Going real wide is going to throw you in a whole other class, and still won't be nearly as effective as balancing the car with the right PSIs and the right line.
As for your 360s, or Carousels as we call them. You have to get as close as you possibly can to the cones and drive right at the edge of available grip. Most people try to go through those much too fast and end up wasting time understeering around it, going wide, and not having traction to accelerate out. You can do great things in these with finely adjusting your line via left foot braking, but that's not something you want to try right away. Just concentrate on getting close and controlling speed so that you have traction all the way around.
As for the 180s, as WD40 said, you just have to take the SIFO (Slow In Fast Out) line, and it also really depends on the gate after it. What's the next gate's distance, angle, etc etc. And what line do you need to have through that gat for the one after it? How you take that 180 is completely dependant on the next 2 sections after it. Sometimes I fly in at speed and get a lot of rotation in 2nd if I have an easy angle and distance to get a good line through the next gate. Other times I hit the brakes hard and exit in 1st if the next section is tight and I need to get on the racing line right away.
Autocrossing isn't mastering a corner, it's mastering the corner you'll be at soon.
Don't waste another minute waiting on parts, or anything else. Just get out there and start racing! You will suck at first, and you will be slower than many other cars, but the only thing you will regret is not starting earlier...