My new car prep usually consists of at least a 1 step polish to get rid of any "dealer installed damage" from auto washing, poor prep, etc.
Being that your car is Pearl White you are in luck, pearl white is one of the hardest colors to see defects on. I would start with a wash and clay, if you don't see any visible defects needing correcting then use the old sealant (I love sealants on white), and wax on top as needed.
