I wouldn't recommend putting a lot of money into a RV and trying to travel full-time if you've never RV'd before. At least rent for a couple weeks (which is expensive) or preferably buy a used one and traveling in it for at least 6 months to see if full-timing is for you. Don't jump into this lifestyle!
Read these forums and you'll find there can be a lot of problems and 'how-to-do' issues that you haven't even thought about. A big one nowadays is medical insurance that you can travel with. You'll have to domicile in the correct state and even in the correct county to obtain reasonable insurance - unless you're on Medicare.
Yes, a mobile hotspot is the way to go and if working on the internet it will be expensive.
Yes, you can easily install solar or there are many places that do it.
Full-Timed for 16 Years
.... Back in S&B Again
Traveled 8 yr in a 40' 2004 Newmar Dutch Star Motorhome
& 8 yr in a 33' Travel Supreme 5th Wheel