Picking out a trailer is always a chore but it gets easier if you can look at a few trailers and make a list of the features you want. Here's a selection questions to ask yourself. I'm sure others can add theirs.
(1) Do I want a toilet? (Never a problem until it's 3AM and the camp toilet is 100 yards away.)
(2) Do I want to be able to stand up in my trailer?
(3) Do I need an air conditioner? (Useless for
boondocking but great if you intend to stay in campgrounds with
electrical service.)
(4) Do I need a
refrigerator? How about a freezer?
(5) Do I want
propane for heating and stove? (Yes, there are trailers out there without gas. Looking at you,
lil Snoozy.)
(6) Do I want to be able to have a dinette without having to take the bed apart? (Some smaller trailers are like this.)
(7) Where am I going to take my trailer and will I have enough ground clearance? (Just paved roads, easy dirt roads, or some mild 4-wheeling?)
(8) Am I looking to buy new or used? (Buying new gives you a few years with few problems. But ALL trailers need work sooner or later. It saves a lot of time and money if you're handy with tools.)
(9) Is the bed big enough for me?
These are just some of the issues you will have to deal with on your quest for a trailer of your own. But if select carefully, you will have many years to enjoy it.