The island is ~4 miles off-shore and has no fuel services - Ashland (KASX) south of the airport has fuel services.
Bikes or mopeds can be rented on the island (give Motion to Go a call for the ride into town). It's a 1.5 mile walk into town if you don't opt for the ride. All the major attractions on the island are accessible by bike.
Big Bay State Park has beaches and trails:
Aerial shot of the main town of the island (La Pointe) which is very walkable:
The rest of the Apostle Islands are not accessible by land planes - so grab a kayak:
Courtesy Car: No, but call Motion to Go for a ride into town for bike / moped rentals
Food: Several restaurants clustered in the main town
Adventure: Big Bay State Park, Kayaking, Bike/moped the island