Most people from overseas will fly. Whether you opt to fly directly to Orlando International, one of the most impressive airports in North America, or whether you hire a car on arrival somewhere else and drive down, getting there is pretty painless. A few airlines that fly directly to Orlando from Europe include:
Rent (hire) a car. That's really the only choice. Buses, while they do exist, do not run very frequently. Fortunately, renting a car in Florida is a relatively cheap proposition. The cheapest rental car rates in the country are there and in Hawaii.
Every time I visited Florida I was visiting friends so they always provided the transportation. The Orlando airport is one of the largest in the country and worth arriving early to do last minute shopping.
I flew from Orlando to Miami once with this flight of Continental.
Very quiet flight, and in less than an hour you're in Miami.
Fast boarding but no meal :-(
I flew from Miami to Orlando once with this flight of Gulfstream.
Very quiet flight, and in less than an hour you're in Orlando.
Fast check-in, fast boarding.
Fly into Orlando International, then Hire a car
Hire a car. There's really very little other option if you want to get out and about.