Nothing wrong with doing track days in a ute.
The light back end will make the ute a little more tail happy than a sedan, but there is nothing wrong with a bit of sliding here and there, keeps the reflexes sharp.
If you do want to find a class to go door to door racing so to speak, the roll cage can be a little more tricky than a sedan to build and fit.
If you are just looking at general track days, the first thing I would do is fit a set of VE 330mm front rotors and calipers and a set of ventilated VE 315mm rear rotors and calipers, pad the combo up with some REMSA pads from GSL and you will be able to do more that 2 laps without the brakes fading away.
From there I would go out and get some semi slick tyres, even second hand ones will provide more grip that a good road tyre.
Then head out to some track days and start to get used to the track and the car and start to learn the lines of the tracks. Once your times start to even out and you become more consistent start looking at suspension upgrades and some more power upgrades.
Most of all have FUN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
