I swear, this is the same conversation I had with my sister and her husband 2 months ago. They got it in their heads that they'd like to buy a 40-footer and do a seasonal 'commute' via the ICW from Michigan to the southeast states, living aboard the boat year-round. No personal boat ownership experience and limited exposure to boats. Nearly all of their savings would be used to buy an older one in decent condition. Ongoing, they believe that the money they save in rent will be more than enough to support the boat.
My short answer was, 'You don't even know how much you don't know'
I think it's great that you've decided to test the waters in a small boat. Terrific start. Now, get some REAL education, and NOT via youtube. US Power Squadrons and US Coast Guard Auxiliary both offer basic boating courses. Take one, and do it in a classroom setting near where you live and boat. Don't know about USCGA, but if you decide to join a chapter of USPS, you're open to dozens of additional advanced courses in seamanship, piloting, navigation, marine electrical systems, engine maintenance... the list goes on and on.
In addition to iboats, join forums dedicated to large cruisers, live-aboards, houseboats, etc. and pose some of your questions and concerns there. The folks here are a truly terrific bunch, but few if any of us own really big boats, or live aboard for extended periods of time.
Keep in touch with us, and ask as many questions as you can think of. Good luck.
My .02
