Can't help with the "entertaining the kids" part, as I have been to Florida a few times but always on my own. A few times were fly-drive, wandering around from area to area in a hire car, finding motels as I went. The Gulf coast is beautiful south of Tampa, around Clearwater and St Petes. Northeast is good too, St. Augustine springs to mind. Can't go far wrong with Super-8 motel or Motel-6. I used to use Denny's for breakfast, actually brunch due to the size of it. Incredibly cheap a few years ago, when the exchange rate was more favorable for us.
Post covid there is a real problem with car hire in USA, as they sold off their car fleets due to lack of demand during covid. Now they cannot get replacements due to shortage of new cars, so car rental costs have shot up. Think £50 per day as the starting point for a small car in low season.
The last few times I went, I didn't bother with a car and took a bike. There is actually some pleasant cycling around Orlando. And wide footpaths where cycles are allowed. Nobody walks anywhere apart from dopey British tourists heading for McDonalds on International Drive, so footpath = private cycle track!
You certainly won't be bored. Kennedy Space Centre is amazing, I spent a whole day there. Actually saw a space shuttle blast off during one of my visits (not so great as you were kept so far from it, it looked like a firework in the distance).
Epcot Centre was interesting.
Suggest buying a Lonely Planet guide or similar, as there is just so much to see and do.