Depends on what you're going to Port Canaveral for and what time you'd like to get there.
If going on a
Disney Cruise, then you can book
DCL ground transfers. They may not pickup at FW I'm not sure. There is a list of resorts they do pickup from, basically the land and sea package resorts and AK I believe. If they don't pickup from FW no problem, you'll just have to let them know what resort you will be at for pickup and be there that morning. I think the earliest DCL ground transportation will get you to the port is about 11:30 or so ....
If you are not cruising DCL, or want to get the port before or around 11:00a.m., then you may want to rent a car or use a towncar/limo service. Many towncar services to choose from as you will probably see many mention on this discussion board.
FL Tours, Tiffany Towncar, Happy Limo, Sothern Elegance, Magic Transportation, etc..... Just to mention a few.