Land and Sea and Land Transportation Question

My wife and I decided to do a three-night cruise, followed by four nights at Polynesian. We're also planning to add a night in a Duo Studio the night before the cruise starts. The hope is that once we park the car, we don't have to move it again until we head home at the end of the trip, and thus not have to pay to park at the port.

Regarding the buses to and from the port, do they cost anything? Do they have a set departure time from the resorts, or do you find out closer to the time? Is it generally an early departure, or closer to midday, given that check-in doesn't start until 11:00 AM?