Do You REALLY want to do this and NOT get hurt?
If you're serious, want to do this sport for a while, and you don't want to crash, you have to think about this stuff very consciously. You should study track maps, trusted-source videos, take courses and/or coaching, work on mental acuity exercises, work on your physical health, etc. Even doing everything 'right' is no guarantee but it will help your odds exponentially.
Nearly all TDPs operate under the premise of 'no-fault,' meaning if you crash, even if another rider caused you to go down, you're on your own. I can't say that I agree or disagree with this but because of it, you do need to cover your own ass. When you ride, try to have an out. If you can't make a clean pass and you've been stuck for 2 laps, ride through the pits to get a buffer. Don't apex bomb, chop other people's noses off, or hop right in front of a rider on a slower bike right before a corner and take their line. If you decide you want to try a certain corner at a speed that's faster than you've done before, don't do it with other riders near you. If you're even the slightest bit unsure about your hardware, get off the track and check it out and fix it, talk to a trackside tech vendor. Don't follow people too closely--you don't know their riding style or their hardware. You can find the limits of your bike, tires, suspension, etc. without crashing if you do it methodically, you just have to work up to it gradually. If you feel the red mist come over you, it's time to pit. If you find yourself making mistakes, it's time to come in or slow down and just focus on skill-building. When you *feel* like you're going faster but your lap times are slower, you're getting tired--either call it or just focus on technique/skill-building. If you’ve got a bad vibe about one particular session, come in early or sit it out.
Budget for this endeavor--it really doesn't pay to skimp on things, be it hardware (bike, tires, brake pads, physical protection, etc.) or software (your own training, both in time and money spent for coaching/schools). This doesn’t mean you have to spend huge money and buy the most expensive bike—I have a load of fun on my inexpensive Ninja 400 (Ken Hill mentions these bikes in a couple of podcasts). Knowing what I do after 3-1/2 seasons of track riding, I should have started out with this platform. For me to find hardware limits on my ‘A’ bike, I’d have to have a pace well beyond where I’m at now and I’m not willing to ‘send it’ to find those limits.
The VAST majority of us don't need to be on slicks. Slicks offer a greater safety net IF you can keep heat in the tires but when I see a C group rider with slicks, I see an accident waiting to happen. When I see a B group rider on slicks, the first thing that comes to mind is someone who would be crashing without slicks, in other words, they're not crashing on slicks because they have the extra grip to cover their mistakes. I am totally comfortable running on DOT tires in A group and in many ways, like it better because I can find the limits of the tires. I'm a long way off from finding that on slicks. By riding on the DOTs I'm trying to develop my own feel for limits of adhesion. Even in the ChampSchool, their instructors ride on Dunlop Q3+ DOT tires. Often times CSS runs not just the students but also their instructors on Q3+ tires. Some of the European schools run on sport-touring tires. For the record, my big track bike normally has slicks but if it’s a cool or slower day, I’ll put DOTs on it or ride my street bike with a mid-grade sporty tire. My Ninja 400, though race-prepped, has Q3+ tires and stock suspension. My goal with that bike is to find its limits. When I feel like I can’t get any faster through technique, then I’ll upgrade components (or keep it budget and just recognize the limits). I’m far from the fastest little bike rider but A group is no problem, even on the fast tracks.
If we want to do this for a long time and continue to improve without getting hurt, we need to be mindful and focused. If done this way, it can be one of the most satisfying things you do in your life.