Not sure how long and how to explore the florida keys
 

Never been to Florida before so heading out of Naples to the Florida Keys- what is recommended time in a few stops, and which islands would you recommend? Want to see Key West but also explore time!

Are you renting a car in Naples and returning it there?
How are you getting to Naples?
Are you spending any time in Miami?

If you are in no hurry, plan on a stop in South Beach, at least for a day, have a meal there, walk around, do some shopping... Even an overnight can be fun if you want to see the night life...

Then consider an early start in the am for an easy drive down the keys... There are dozens of quirky stops, sights, shopping and food along the way and you should expect a leisurely drive.... Islamorada is about half way on the five hour drive and a good stop... Key West is at the end of the route, but hotel checkin is often after 4pm...

Might be helpful to know why you chose Naples to start out from. Also be helpful to know why you've decided you want to go to the Keys. Your interests and motivation would also be helpful to know before we recommend any island, much less any city, to spend time in.

That said, there are probably a few people who might tell you all the places you have mentioned are questionable, and that includes Miami!

http://ferryservicestokeywest.com/

If you don't want to drive you can do the ferry, drops you right off in KW and you don't need a car. We blow through everything except for a lunch stop and go directly to KW, same for coming the other way.