I'm pretty sure you could mount a Go Pro if you have one. They offered a gadget that you could rent and record your driving in the car, so really don't see why they wouldn't allow you to use yours...but you never know. They had us in one car for the two day...due to this ridiculous Covid-19 thing. Upside is once your get it adjusted, you are good for both days.
Honestly, I paid half price ($1649) for the two day. Would not have been worth it for me if full price of $3350. Not sure if three days would've been worth the extra...maybe I'm just expecting too much. If you have extra money burning a hole in your pocket, let 'r rip, I'm sure you would get something out of it. For me, putting that toward an HPDE or brakes and tires will be better spent for me.
If you don't have a helmet, I would shop around, buy one, and bring it. Otherwise you might be able to work that with them. For the two day HPD, you only use a helmet for the track time in the late afternoon of each day, like less than an hour each day. If you won't need a helmet after you do this course I would just borrow one from them, just work that off line as a side bar, not open forum.
HTH