Not sure about the first two polishes, but the 106 will finish down the best, but also has almost as much cut as the first two, so you may want to try that first.
As far as process, unless your car is really bad, use a polishing pad and the 106. If that doesn't work, move up to a cutting pad.
I'm not too experienced yet with
Menzerna, but as a starting point, put a couple lines about two inches long on the pad and dab it in a few spots on the paint (about a 2 foot square section). Turn the machine on to setting 3 and make one pass on the entire area to get the polish spread. Then turn it on to the top speed 6, go slow (about 2-3 inches per second) and polish the area several times (like first up and down once, then side to side, then up and down, etc). I would try doing 3-4 passes (u/d, then s/s, then u/d, then s/s again) using moderate pressure (push down on a scale to about 10-15 pounds for an idea). Then do like two more with little to no pressure a bit faster. From there you can experiment with how many passes you need to make, speed, etc. based on the paint of your car.
I'm sure more experienced users will chime in as well.