Welcome, "Old Man"! Okay... sounds better in Finnish...
Backing will come with practice. Don't hesitate to pull forward and take another run. Because of the short length, a little steering input goes a long way. Go slow, and pretend nobody is watching...
I started backing a tent trailer before I even had a driver's license
. My parents weren't too fond of backing, so they would let me take over when we got to the campground, and of course I was happy to oblige! If it helps, a Scamp
13 is one of the trickier trailers to back due to its short length and curved sides.
Enjoy your first season, and may there be many more to come!