Unless you have caked on dirt or mud, a rinseless wash routine using something like ONR or Mckees 37 N-914 works great. I pretreat the dirtiest areas using an ONR solution applied with a garden sprayer. While that is dwelling on the paint, I perform a rinseless wash starting at the top of the car and working my way down to the bottom. The important thing is to make sure it is not in sunlight or hot enough that the ONR solution dries on the paint.
As for wax, yes, I would avoid applying paste wax or even a white liquid wax. When I got my Xpel PPF installed 2 years ago, I first tried the Xpel PPF sealant. Despite my efforts to keep it away from edges, a bit of it did get wedged along an edge and looked bad. So I suggest using a PPF-safe spray sealant such as Turtle Wax Seal and Shine, The Last Coat 2.0, Technicians Choice Ceramic Detail Spray, or Xtreme Solutions PolySeal. Unlike a paste wax which runs the risk getting trapped along the edge of PPF, a spray sealant will wipe away completely clean.
As for cleaning and maintaining PPF, here is a helpful video from Larry at AMMO NYC: