IMHO the biggest thing you NEED to remember is when at the gas station if you need to turn on the way out you WILL hit the pump with the back end of a 31 foot. MH !! :B
You have to plan to make sure you can pull up straight away from the pump enough to clear the rear of the MH before you turn, so the tail end doesn't hit the pumps.
I.E. if you are pulled up along the pumps on the drivers side:
If when you leave you turn to the right the tail end hits the pumps.
Congrats on the new to you MH. Happy Camping! :C