2 points
If the walkway goes inside the building, then yes. And the walkway usually leads directly to the second floor, because the airplane door is 3 metres above the ground.
2 points
*
OK but what about going onto the ground?
Like, in your garden, is that the first floor of the planet?
1 point
Inside the building it’s the first floor, even if it’s exactly at the sea level altitude. Outside the building it’s the ground. Basement levels start at minus one, there is no zeroth floor.