Eeek flights booked, itinerary help needed!

[Gemski]

After seeing flight prices we were happy with and not expecting to go back for a few years, we booked last night so now have a new countdown 😍
After a few trips under our belt and needing this to be a "cheapish" holiday we wont be doing the major parks. We are flying in and out of Miami and will have 12 nights but so far have no accommodation booked. So my question fellow dibbers is, what should we do?
We were thinking a couple of nights in Miami then driving up to Orlando for 10 nights and having a bit of chill time and seeing things beyond the parks.
Planning a trip without parks is a little alien to me so suggestions would be much appreciated. We are a party of 2 adults a 12yr old and 10yr old.
Is Miami child friendly?
Is 2 nights in Miami too long or too short?
Should we maybe reduce our time in Orlando and do a bit of a road trip?
We may consider buying the 3 park SeaWorld, Aquatica and Busch ticket as they seem a good price but im a little worried they will be too busy for us to really make the most of them.
We are on an accommodation budget of around £100 a night. We don't mind sharing a room I till we get to Orlando but we would then want a 2 bed condo or similar, preferably with resorts facilities like a good pool, slides sports facilities ect. Any accommodation recommendations would be great too 😊
Sorry for all the questions and thanks in advance for replies.👍😀