Every couple of months or so my friends and I will rent out a track near Victorville called Grange Motor Circuit and invite anyone that is interested. We can run 10 cars on the track at the same time so you can get as much seat time as you want. We also can provide tips and help along the way. Here's our website https://www.racefreely.com/
(sorry it's still a work in progress) We are not for profit in anyway and all the entry fees goes to track rental, insurance, and food. Keep an eye out on the western members forum for our Post.
Anyways looks like you have a pretty good setup at the moment. You'll surely want to get that rear sway bar on that'll help a good amount. Also you probably don't want to have the LCA in the lowest setting, as the lowest setting is best for traction and drag racing. You'll want to set it so the LCA is parallel to the ground, so usually just the middle slot to best reduce roll steer. In the future you should go with a square tire setup as well so you can rotate the tires anywhere, have a better balanced setup and reduce the risk of freaking out your ABS.
I don't have much experience with many different brands of brake pads yet, I just switched to the Hawk HPS but that is for the CTS-V. Our cars come with too high of rear bias braking causing the rear wheels to lockup first, so you might leave your current rear pads on and get some more aggressive front pads to balance it a bit better.
Diff/tranny fluids will be fine with the stock stuff, be a good idea to get a nice diff cover with cap supports to help the 10 bolt last a bit longer, and if you have an auto you'll want an additional tranny cooler.
Radiator flush you'll just want to flush out the dexcrap and swap in the green stuff.