Yeah, go to a few RV shows and look at what floor plans are available. DW & I looked for 2 years for a replacement for the hybrid TT we had. After having the HTT for 8 years we had a list of must haves, nice to have, and don't care if it has it or not.
Do you want a couch or not? A slide? Dinette on a slide, or dinette & couch on the slide? How much storage does it have both inside and outside? Lightweight construction, or stick-and-tin? My wife's biggie - a walk-around bed, not one with the foot right up against a wall. And actually sit on the toilet to see how much room you have, some floorplans are tight on room for your knees. Other floorplans don't leave you much room when standing at the bathroom sink.
Your truck will tow it just fine. What's the payload listed on the yellow door sticker? If you start loading the bed with stuff like firewood, a generator, and other gear you can run out of payload long before you hit the towing limit.
If you've never owned an RV before and want to buy used I'd have another knowledgeable person look it over for possible problems, the biggest being water leaks in the roof. Also consider the age of the tires and if the brakes & wheel bearings have been serviced.