It's about a 10-15 minute walk, or you can take the boat or bus to the parks. If you drive, then you will have to pay additional $ to park (if you don't have an AP). Plus, the walk from the parking garage to the parks can be just as far.
The boat drops you off down in front of Nascar Cafe. It is the central pick up/drop off area. Then you have to walk around the pond to either IOA or USF.