I've only been to the track a few times but the first thing I would personally do is pickup an 18in track set. My PS2's get pretty shredded once they heat up (100 degrees didn't help). If you plan on going to multiple events it makes sense. Plus it allows to play with tire widths and air pressure setups. On the safety side, you'll always be rolling on non tracked PS2's for your daily driving, I feel that will add some peace of mind.
The OEM 18in" are BBS's and there are plenty of sets being sold for cheap usually. Slap on some Advans or any other extreme non R compound tire and have fun. The tires will be cheaper to replace and you'll get the chance to experiment.
Otherwise I would just pick up some small stuff, gloves, jack, air gauge, a GoPro and mount so I can watch and review what I'm doing right/wrong.