Here's a (very) basic starter's kit:
We use Vacations To Go,
Repositioning Cruises, Repositioning Cruise, Cruise Repositioning, Repositioning Cruise Line, Repositioning Cruise Lines
(you'll need to provide an e-mail addy for access), to see all the offerings
they have listed....(there are others around, but this is just an intro)......scroll down until you see a price you like, for a ship going from a port you'd like to see and arriving, (generally, but not always, in Florida), somewhere convenient.
Once you've selected a trip that might be interesting, click on the underlined number on the far left column....this will show you price/itinerary, and above the cabin price menu you'll see the ship's name....click on it for pics and info about the ship.
What to do in a (any) port before the cruise? First, find somewhere to stay for the duration....we generally use airbnb or perhaps House Trip (there are others...and always read the reviews). Then perhaps Google the city's Tourist Board for things they suggest you might like to see; that, and maybe somewhere like Trip Advisor for suggestions.........or, as we often do...wander around aimlessly....serendipity is your friend.
Flights? Check out a bunch of Search Engines, plug in your date(s) and see what they come up with......don't be afraid of trying airlines unfamiliar to you.....we've used Turkish, Polish, Norwegian, Russian, Indian, etc, etc, airlines with no problem.
Rocket Surgery it's not.....get going!