Stay far away from the autozone kits. Meguairs has some really great stuff in the pro line. Clay with the Pro
Detailing Clay. To get rid of swirls I highly recommend a palm orbital with
Ultra Finishing Polish #205 followed by
Synthetic Sealant 2.0 #21. I like the
Softbuff Polishing pad for the #205 and the
Softbuff Finishing pad for the #21
Feel free to PM me if you want further detail but if you do this the right way your car will look way better than it did new and you will have zero swirling. The best part of this is its next to impossible to swirl your finish while doing this.
Plan on spending a few hundred dollars getting this stuff together but you will never look back to any other products after you go this route.
With your car being black you will get a mirror finish void of even fine scratches and the paint will look wet.