I suggest you search and read the track forum, including a thread such as this:
Optimal ride height for track setup
As well as this thread, since wheel and suspension go together:
Wheel Fitment 101: START HERE
In general though:
You'll want an entry level coilover but not one of the crappy ebay level brands. Throw your springs away. Look at Fortune's 500 series, Powertrix (Z specialist), or BC racing
We have no front camber/caster adjustment and limited camber/caster adjustment in rear. The best and only solution is SPL parts:
https://www.splparts.com/09-370z-z34/
You will need their front upper control arms, rear camber arm, rear traction arm, and either the toe arm or midlink depending on your type of coilover. True type (spring around the damper) requires the toe arm; OEM type (spring divorced from damper) requires the midlink. Used versions of these parts pop up in the FS section, keep an eye out.
SPL stuff has the best adjustment range and a secure locking mechanism that is also the easiest to adjust for your tech. They will love you. They are track proven and also give you the adjustment for an essentially infinite range of wheel fitment
The final component of this area is the wheels. For track, generally proven setup is 18x10.5 or 18x11 in the +12 to +20 range (or thereabouts) with 275 or 285 tires. For beginner, something like a 200TW is probably a good starting point
Sport brakes (akebono calipers) can hold up on track with better fluids, new pads, and calipers, but cooling can be an issue. brake ducting, titanium shims, 2 pc rotors all help. At higher skill levels, better hardware may be required, but thats down the line
On the practical side, you have to have a helmet to track, thats non negotiable. You should test before buying anything, and make sure it is certified. You should also test IN CAR to make sure you fit with the helmet. If you cannot fit, move to next step:
Seats. 2015+ Nismos have recaros that hold fine, but if you dont have such a model you will need to look at an aftermarket bucket. Again, test before buying. Do not buy a seat you have not sat in. Depending on your height, custom work may be required. I'm just under 6 ft but have a long torso so i have clearance issues