if the trackday isn't open pit, go in novice, and use your mirros A LOT

as you will be new to track, other people even novices will be fast, so use your MIRRORS

make sure you have ZERO oil leaks and brakes and suspension is up to the job.

and TYRES, and tyre pressures are correct for conditions

check you have enough oil and water too

then take ya time, it's not a race, and make sure you do warm up laps and cool down laps, it helps the car recover