How does a new truck camper camper get started?

You don't say why you want a truck camper.  Some do buy a truck just for truck camper, but keep in mind that a truck/truck camper combination is one of the most expensive RVs for the space you get.

I suggest going to some of the larger RV shows that will show you all of the types of RVs that are out there and demonstrate different floor plans.  If you look at the schedule, there are probably some within a short drive/flight of where you live.