I strongly recommend a used one first. For starters, there’s no guarantee that you will even like the experience. Second, the floor plan that you first thought would be perfect or at least sufficient may turn out to be something you really don’t like.
Will you be doing any off grid camping? If so, look for the biggest holding tanks available.
Going to the shows is a good idea. If you find something you like leave your contact info with the salesman in case he gets a good trade in. Do some online shopping to get an idea of what you may like.
Lastly, keep me in mind, I love rv shopping and I get a tat jealous.
Happy shopping!!!!