...those above are giving you the right advice - if you already have a liter bike, no need to rush selling it off to get a 600 just so you can go to the track.
Rememer, everything on the 1 is more (more power, more torque, more hp, etc).
So trying to wring the chit out of that thing will cause nothing more than body injuries to you and body injuries to the bike (read: your pocket book).
So if you already have it, make sure you prep it according to the rules of the track host (they will have the info on their web site, if not - call them).
After that, ride at no more than about 70% of your comfort level with the bike. Your first track day should not be about how fast you can go. It should be (and this goes for all first timers to track) all about the line, and making smooth transitions from gas to brake, and steering.
This will take up a large chunk of your time during the track day. Forget about others who just buzz by you - they either signed up in the wrong level (should be in intermediate but are too chicken to do so), or are riding way over their head and will eventually cause a wreck (trust me - you do not want to be near them when that happens - it is often messy).
So make sure you ride only for yourself. If you bring friends with you, it is actually a good idea not to grid together because you will eventually want to play together and will egg each other on to ride faster and faster until you both are beyond your safety and capability limits. Then, it is a 50/50 if you go down, and the longer you do it, the larger the chances you will have an event.
So the important thing is to give yourself a huge margin for error, so you can react and stay upright. Lines and smooth transitions are the fundamentals without which you will not progress beyond mediocre rider capability. Too often do we see in school riders who think they are the fastest think on 2 wheels, but when we observe them, they are erratic, unsafe and riding on the edge of falling down. I have shot so many vids of riders who just beg to lay it down by riding unsafe, and it is a shame to see especially since we speak to them and tell them about it, and they do not adjust at all.
My favorite quote is: Slow is smooth - Smooth is right - and RIGHT IS FAST!!
So you want to be fast, begin by teaching yourself the right habits by riding slow, smooth and proper.