Wash the vehicle.
Then decontaminate. You can use clay, a clay substitute (mitts/block etc), chemicals like tar and iron removers, or a combination. Claying would, IMO, be the one step I would not leave out. With white the cleaner you get the paint the better it looks (as with all paint, but white tends to contrast with the dirt on paint more than say black, which tends to contrast with swirls better) so I agree, if your budget allows it, then adding in an iron remover step to be sure you have removed ALL of the iron contamination (which to me, makese sense when you are starting out with a new car) is definitely a good thing.
Then when it comes to selecting a polish you should conduct a test spot(s) starting with your least aggressive combination of pad/polish - in this case SF4000 is a good starting point. Their paint is somewhat on the harder side (generally) so perhaps if you really needed to on a brand new car with some heavier swirling, a medium cut polish would be needed (say like PF2500). You will only know what works for you on your car, once you do your test spots...:dblthumb2:
What machine, pads and polishes do you already have?