First, do NOT be intimidated by the size of your new to you RV. There are various assets on the Net with videos, etc. for learning RV driving skills. You might want to consider the RV Driving School, www.rvschool.com. They have locations throughout the US.
The main things to remember are 1) Take your time. Never be in a rush. Another hour does not matter in the grand scheme. 2) The right lane is the RVer's friend. Let the other fools drive down the road at 70 with a trailer or toad behind.It takes a long distance to stop an RV and even longer with a tow. 62 mph is fast enough when towing, 60 even better. 3)Adjust the outside mirrors so as to have a good view of what is coming behind and along side of you. All you need to see of the RV is a sliver of the rear in the mirrors. 4) ALWAYS have a spotter on the ground when backing up but I think you know that from your OP. 5) Generally when turning you should start your turn when your HIPS are aligned with the curb, corner, etc, where you are turning. If you have to swing wide to make a turn then do so. If you need to hold up traffic in order to safely turn then do so. The people you are holding up are more than likely strangers who you will never see again, so why care? Always err on the side of safety.
I am a certified RV driving instructor but am retired from that fourth career.