When I pick my plane and airport i want to be at adn check download scenery it takes me to the screen and loads up, but im not on grass or anything, jus grey water.
For the first time you select an airport that you've never selected so far, you may be on the sea.
In this case, wait for a few minutes so that FlightGear can download the scenery data around you.
Then, quit FlightGear and launch again. This time you will be on the airport.
Exactly this is it for me too but I've been on an airport more than two times but nothing comes up, and I've waiting but nothing happens…