Starting a thread to share some of my experience and I hope other will bring their questions or experiences to create a topic everyone can learn from.
As always, there are no dumb questions, so please feel free to ask.
HPDEs or track days are a great way to spend time with your friends, test your skills, your car, or safely explore the limits of each in a controlled environment.
In my experience, the value is beneficial not only in terms of seat time but in the skills you can develop that really do translate in day-to-day driving. That means not driving like an idiot on the street, but it gives you an instinctual feel for your surroundings and the experience to handle those sudden situations.
The first thing I tell anyone interested in doing a HPDE is accidents DO happen. They can be rare, but you have to starkly aware of the risks and dangers. My most common response to interested people is this:
"Are you prepared to walk away from your car as a total loss?"
It may be a bit alarming, but it is a distinct possibility. It isn't meant to scare people, but it does make them think.
YOUR CAR
A lot of times, people who are going to run in their first HPDE think they need to get all the modifications they had planned on completed before the event. This is completely wrong. What you need is your car to be completely HEALTHY and mechanically sound. This means fluid leaks, wonky steering components, questionable interior modifications, all need to be addressed. It is FAR better to have your car up to date on maintenance and be safe, than to be 'because racecar' and dangerous.
Each HPDE organization requires a thorough tech inspection, but each are a little different in who performs it. Some require you to have your car inspected my a mechanic, who will check items on the organization's list of requirements and sign off on that sheet (you must bring to the event). Some will inspect your car at the event before you are allowed on the course. If you forego repairs, you risk wasting your time and money by being rejected from participating.
The key here is to be smart, get your car up to snuff. NO ONE wants to be 'that guy' who dumps fluids on the track, has a mechanical failure, or puts others at risk because you won't keep your car maintained.
YOUR SAFETY GEAR
You are going to need a helmet. It is going to have to be up to date and you are going to have to be sure it fits. Motorcycle helmets are NOT the same as SA-rated helmets and most organizations will be very strict about this. There are many vendors who sell them online and offer sizing guidelines to help you make sure it will fit.
You will be required to wear pants, close-toe shoes, even long sleeved shirts. There is reason for this and it is all safety-related. I suggest wearing as much cotton clothing as you can, in case of a fire. If you feel you want buy a driving suit, neck restraint, balaclava, etc. More power to you. As mentioned above, the risk is there, so hedging your bets on being over-prepared is a good thing. Many don't and that is fine too. It is a choice. I would suggest a pair of gloves too. You can use mechanic's gloves or something similar, but they serve a few important purposes; first they help act as a barrier between your sweaty hands and the controls, secondly they will be immensely helpful should you have an incident were you need to get out of your car and there is broken glass or twisted sheet metal between you and exiting the vehicle.
In a Miata, you will be required to have an approved rollbar. If you don't know the difference, we can discuss it below. Simply having your top up or a removable hardtop won't cut it. In the event of a rollover, the hardtop is going to leave the car, sometime quite spectacularly. Please get SFI padding for your bar, too. If you run topless, you may have to get arm restraints that prevent your hands from flying around in a rollover or accident.
YOUR FIRST EVENT
Arrive early. If you miss the driver's meeting, you don't participate. It's that simple. Show up early, give yourself time to get oriented, relaxed, focused. It also helps the organizers to move things along smoothly. You may even get to meet your instructor ahead of schedule and chat them up to release some nervous energy. Yes, you will and should have an instructor who will ride along with you. They are there to make sure you are safe, understand the course, and have a working knowledge of the layout and corner stations. Listen to them. They aren't there to chide you, laugh at you, they are there to help you learn and enjoy yourself. If you ignore the instructor, you will be ejected. No refunds, no sympathy.
Be aware of the rules for your run group, the order you run in the event, and the day's schedule. If you miss your heat, you have to wait for all the groups to cycle through until your group is back out on the course. It's a social event, so just be aware of the time and when your are allowed to grid. Use that time between heats to check your oil level, look for leaks, get come water, maybe even find an advanced driver you can ride along with. It can be an eye-opening experience to ride in another Miata with an advanced driver, particularly if that car is less modified than your own.
It is important you stay aware of your condition, as well as your vehicle's. Remember to eat something, stay hydrated, reflect on the previous heat and where you found yourself not performing as well as you hoped. Some like to review their videos, discuss corner entries, braking points, etc with their instructors. That is perfectly normal and expected. It is also best to reflect on your limits. You aren't going to go out and be King of the Rookies, so keep your ego in check. There will ALWAYS be someone faster.