If your just getting into it rent a few in different sizes and floor plans see what you like or don't like ( walk around bed, or bed you have to crawl over your partner to get in and out of think middle of the night, bed you have to put up and take down each day,etc) and it will give you an idea what your truck can tow. If the truck is to small wait till the lease is up and get a bigger truck. You will have a better idea what you want in a trailer and what size trailer and truck you need.
You may rent a few times and decide you don't like camping and you will be money ahead.