First thing I'd say is, on your "first look" at CW, is that don't let that be your first mistake if you buy from them. There have been many horror stories here on both the initial purchase and more on getting warranty issues dealt with. I'd look at an independent dealer. However, many of them are useless as well, especially on getting warranty problems fixed properly, if at all. I'd do some investigating on a dealers's "quality" before buying. Anyway...
Our first TT was 20' overall (with dual axles) and was towed with a reg. cab truck. That was a nice length and allowed us to drive around Walmart and Freddies parking lots EASILY all day long. Could even park in two end-end parking spaces. Never had a problem backing it up and in one CG I had to back it up about 1/4 mile on a twisty road to get into the last available site in a CG. Our current TT is 29' and there's no way I can drive it up and down the lanes in parking lots. We now tow with an extended cab truck and the extra wheelbase also makes it harder around turns. Not sure around what length it starts to get noticeably more difficult to get around turns. Personally I find our 29' TT harder to back up into a site because when the truck & trailer are at an angle, it blocks your view rearwards more and is harder to get a sense of where you're at in relation to obstructions and getting aligned where you want to be.
There have been countless discussions on single vs dual axle TTs. I'd look at the FR R-pods. I think they look cool but they don't seem to have sofas. A slide out makes a BIG difference in a TT.
The biggest issue we had in our 20'TT was that the kitchen counter was directly across from the bathroom and passing each other all the time was a PITA due to the narrowness of the aisle. For one person only, I'd definitely be thinking about where to sit comfortably for extended periods, whether watching TV, reading a book, etc. Dinette seating is not that comfortable and sitting upright in a bed isn't comfortable either. Some smaller TTs have a murphy bed which might be something to consider. Perhaps get a rear picture window model - they let a lot of light in and can make a small space feel less claustrophobic. A bathroom with separate toilet and shower/tub would be better.
If a first RV, it might be a good idea to rent one and get a better sense of pros and cons between different makes & models. Some CGs have permanent rental TTs on site. One annoying thing with any RV can be the kitchen counters with almost zero work space and some are better than others. Or something as simple as where to have a garbage container (hanging a plastic bag off a knob on a stove is so annoying). You want to avoid finding annoying things after you own a TT. Selling down the road and replacing it can be a costly mistake.
Choose wisely... :)
