Wow! Yeh, 5'2" going on 6'5"

I think you'll manage, just fine. Welcome to the club, get ready to be overwhelmed. 'Sounds like you're off to a great start, have done lots of good work already.
Indeed, lots of 5'er owners to help you with those questions.
In general, Used is the way to go. The depreciation free-fall settles down after three years; many lightly-used rigs still feel new at that point.
Not to sound hypocritical; but, there are RV shows in Dallas and Fort Worth very soon. Dallas' show at Market Hall is in late February
HERE. Fort Worth is not as big, but it is coming soon, kicking off January 5th at the Convention Center
HERE. Walking through several dozen new units will at least give you ideas, and there will be no shortage of salesmen and friendly RV'ers to answer questions.
We just did a trip to Canton, were amazed at the number of RV parks within a stone's throw of I-20.
RVParkReviewsTexas is a good starting point to find additional sites. You'll want to carefully preview candidates: some that cater to fulltimers aren't all that great. But, many are truly nice, like tidy little towns.
Another benefit of site visits: you might meet folks who do exactly what you're proposing. Nothing like sitting at someone's kitchen table and talking about weathering August/January in Texas, managing the wastewater, planning grocery shopping, etc. when the person opposite you has done it for years.
Best of luck!