This is one area that once again proves, there is no substitute for experience.
Practice is the only way you are going to get good at it.
If you are really green, I strongly suggest you have a knowledgeable spotter so you don't damage your trailer, or your towing vehicle. It takes a while to realize where you can get in trouble, jack knifing, or backing into things.
To test the theory that it's easier to learn things, when you are young, I started teaching my Great Granddaughter to back up a trailer at 8 years old. We started out using a mower, and a lawn cart. If it's true, she should be real good at it by the time she gets her drivers license.