Hi,
If you are looking at portable carports, then don't plan on living in a snow area.
My suggestion is get a lot of wood and build something attached to either the side of your house or garage. Check the span, and snow load requirements. It might require 2X10's on 16" center or even 2X12's. Your roof can not be flat or less than 3" rise for each foot wide it is, due to the snow load. It probably needs to be as steep as the average homes in your area. So it might require 4" rise for each foot of width.
I would recommend at least 12' width. I tried parking a 40' X 102" motorhome in a 42' garage with 12' wall to wall. Getting the mirrors between the 11' door opening is difficult. It must go straight in, as any curve will make the motorhome to wide to fit in the door. (OK try it. Take a 8" wide sheet of paper and place it into a 10" wide garage. If it is straight and has 1" mirrors, it will fit, but put it at a angle and it will not fit.)
So if it is 14' wide, then it needs to have about 4" rise per foot, the higher side will be 56"higher than the low side, or if it is a peak roof, then 28" on each side.
Anyway I have to sign off now.
Fred.