As a a fellow 5th wheel owner, I understand your worries. However, also as a fellow 5th wheel owner, you NEED to be able to handle things like this....period. Not to preach, but you need to go practice somewhere and feel confident in your abilities to handle the trailer forward and backward. It is inevitable you will end up in a situation you did not expect and backing out might be the only way to exit it. So nevermind a campsite, what happens if you need to backup somewhere else? A closed road, down tree, etc?
And ALWAYS backup with a spotter you can see in your mirrors! Rearview cameras help, but are no substitute for a spotter. I see in a lot of trailer forums/groups where people think getting a "backup" camera turns parking a trailer into a 1 person job. It might see things directly behind the trailer, but doesn't let you know if you about to catch an overhead wire, your trailer wheels are going off the pavement, an unsupervised kid zipping by on their bikes, etc. It is an absolute team effort and the driver is only as good as the spotter
So hitch up, go find a big shopping center parking lot on an early Sunday morning, and practice. You can do it! Just get some practice in and the confidence will come with it!