There are no trains on the Maldive Islands.
Car and bus
The airport is located on a separate island, 3 kilometers east of Malé, the Maldives' capital. Because the airport lies on an island, the capital cannot be reached by car or bus.
Car rental Malé Airport
Since Malé Airport lies on an island you cannot rent a car. The connections between the islands are maintained by water taxis, ferries and (water) planes.
The only way to get from the airport to the capital Malé is by boat. You can rent a private boat (more a water taxi), but there's also a regular ferry (24 hours per day). The ferry is located outside the Arrivals Hall.
There's a small parking lot outside the terminal, but it's mainly meant for official cars.