Do you have an RV rental place in your area? Even just renting for a weekend and driving a few miles will give you a sense of what you can live with as a floorplan based on your budget. If you are going for under 26 feet and want a rear bed, expect that it will be a corner rather than a walk around in most cases. (Forest River has a couple of exceptions) We are in a 24 foot rig (25.5 actual length) and enjoy that it gets us into many places that we otherwise would miss in our local area. Keeping under 30 feet in total length though still gives a lot of options for places to go, although you will see on this site folks with larger rigs that still find some awesome places to camp that work out. If buying new, the drawback of fall purchases unless you are in a southern climate means that the typical "1 year warranty" for new is nearly 8 months past before you get to use it and address any of the 'gotchas'.
Some say that your first rig will not be the one that you ultimately settle on as your favorite. I can attest that I had a popup trailer, travel trailer, a 22' Class C and now a 24 footer. The temptation of "just a few more feet in length" is a lure. "If only I had 2 more feet we could have a walk around bed..." If only 2 more beyond that and we'd have a couch instead of a dinette..." etc. etc. That's where doing a rental night or two with different floorplans is a nice investment before the big purchase. I would have saved one of my purchases as a result; only lost a little because I was going form one used to another.
History: '08 View, '05 Chinook, '01 Jamboree 24D, '78 Apache Popup, 81 Komfort Tlr,
84 Mazda B2000 'w canopy,
Tent from wedding shower in '96