I was there on my first track day last month, it was fantastic

It is very addictive

But good advise has already been said by Eagle, take your time for a few laps get to know your corners and lines. Then you can build your speed up as you go along

Remember all your fluids, plenty of everything as 1 lap session can equate to 100's of road miles

Finally after a good few laps and you come into the pits make sure you have some chocks of wood to place under your tires as you don't want to put your handbrake on striaght away. the heat soak can warp and damage you brakes Just leave them to cool for a bit

And lastly! ha

Enjoy it!!