One thing you will find.. Even though you have handled "BIG RIGS" this motor home will feel BIGGER.. Trust me (And in this case my brother who is a retired over the road Semi Driver) THEY ARE BIG
The reason is this.. Only two types of vehicles are allowed on the road without oversize permit if they are over 8' wide (96 inches) and those two are Flat Bed Tow Trucks, and either Motor Homes or RV's which are allowed to be 102" wide.
That extra six inches makes a BIG difference.
So find a Mall, after hours, and drive it around a few times to get the feel of it.
And then.. ENJOY..
Others have talked about the length so I will not. I drive a 38' gasser myself.