Have Some Fun with a Trackday
First off, and most important, is your tire set-up. If you're sensible you'll buy a more track focused road legal tire, but even an OE sports tire can just about cut it on track, especially if it's your first time.
Make sure they're in good general condition and that the tire pressures are adjusted to suit the weather and track conditions.
The good thing about trackdays is there are plenty of instructors there to answer specific questions and help with decisions like this. Ideally, when at full temperature you want the pressures to be around the 33psi mark.
If you have a newish motorcycle and the pads haven't worn much you should be able to leave well enough alone. However, if your pads are worn, the fluid's old, or hoses perished, the minute you hit the track they'll soon get found out. The last thing you want is spongy brakes so get them in top condition before, not after.
Similarly, your suspension may well need firming to deal with the added stresses of track riding – depending on your pace and motorcycle.
Lastly, you'll be made not to fit some sort of crash protection. No matter how careful you are there's always the possibility of getting involved in someone else's accident. Also, tape up your mirrors, lights and indicators. They could act as a distraction to you and others around you. Remember to reset all parameters back to road settings before riding home, and that trackdays are supposed to be fun.