Whatever you do, don't let folks around you pressure you because you are taking too long to backup. At some point this will happen. When they start honking, just smile and wave. When they get out of their cars/trucks and walk up to offer to help, just tell them, "No thanks, I gotta learn to do this."
Unless of course you are in danger of damaging your equipment and/or the campgrounds.
If you have electronic brakes on your rig, and it sounds like you do, be sure to test them before you start driving. Make sure they work. My wife did not several years ago. Almost killed herself and certainly total both the truck and the trailer because of it.
Not trying to scare you but there is no time to make adjustments when traffic comes to a sudden stop in front of you.