Consider practice walks at your local park or mall. And try on all the clothes you plan to bring, so that if you have to replace those worn-out shorts you won't be paying resort rates. Mears and Transtar offer shuttle bus service to nearly every hotel in the Disney area. Just show up at their curbside kiosks. For groups of three or more, town car service can be cheaper.
Cabs are usually more expensive.
If you rent a car be sure to pick up a road map. Walt Disney World is an easy 25 minute drive from the Orlando International Airport. Still, there are other factors to consider. Resort guests also save by using Disney's free transportation system in lieu of a car rental. You don't have to ride every ride to get full value from your ticket.