What city is the cheapest to fly to from Florida? We will be traveling all over Italy so it doesn't matter to us where we start. From what I have found so far, Rome seems to be the cheapest.

So then I guess it's Rome. Sounds about right. It would probably be that or Milan

If Milan prices are the same as Rome, fly into one and out of the other to avoid backtracking. Even if it's a few more dollars it will keep you from having to buy a train ticket back and using a travel day to backtrack.

Milan is generally cheaper for us and we fly from Orlando.

Check the multi-city option (into one city, out of another) when searching for flights. I like to use kayak.com.

It still often makes sense to fly into Milan and out of Rome even if prices aren't the same (depending on which cities you plan to visit). It would cost 91€ ($130) for a train ticket back to Milan from Rome plus the train ticket to the airport (7-13€) and loss of sightseeing time backtracking. The r/t in and out of Milan would have save at least $140 over a multi-city ticket to make sense.