IMO, since this car is a 'virgin,' you should go through a somewhat extended (relatively) process of wash, clay, light polish (swirl remover) then wax/sealant depending on the color - light or dark. Claying is a no-brainer, there are a ton of ways that contaminants can attach themselves to the paint and only a good claying can remove them. The down side to claying is that while the clay itself will not scratch your paint, some of the contaminants it picks up can. Granted the scratches they leave will be small, but they will be there, and will be especially visible on dark paint. This is where the swirl remover comes in. Not only will it take care of these minor imperfections (plus I bet the dealer at least washed the car <improperly> for you leaving swirls), but most polishes have a chemical cleaning action to them that will remove what the clay didn't...light oxidation - yes even on clear coats, and the like. I have a SS red car and while clay does an excellent job of removing contaminants, it does nothing for fading/oxidation, leaving the car off-red/pinkish, which for me, Klasse AIO (advertised as NON-abrasive) took care of nicely.
Once you've washed, clayed and polished, your paint should be nice and clean, but the "pores" (microscopic hills and valleys etc) will be open and susceptible to accumulating dirt and contaminants again, this is why you need a good wax/sealant, to close off these "pores" and prevent dirt & contaminants from getting in and dulling your paint.
Picture a slab of concrete, it looks smooth at a distance, but when you look closely, you can see all the hills and valleys...that is the same as your paint...where dirt and debris can collect. A layer of concrete sealant will close off those valleys, preventing the dirt/debris from collecting, the same as a paint sealant does for your paint. Now all that's needed are regular washings to remove dirt etc, from the surface of the paint where they've collected. This is when you start using the baggie test, after the paint has been properly cleaned and sealed. I would say every few weeks or so, unless you notice unusually fast erosion of the sealant layer, such as behind the tires from kicked up road spray, or bugs that don't want to come off during the wash.
Other than that, once everything is done, regular washings (depending on weather conditions, & your Obsessive-Compulsive level...I can do it 2 - 3 times a week easily if the wife lets me) should be enough to keep your car in good shape between touch ups of the sealant layer.