What does it mean when someone says that they've got a foot in the door?
"get a/your foot in the door" (British, American & Australian) also get a leg in the door (Australian) to start working at a low level for an organization because you want a better job in the same organization in the future.
"I know it's not the job you'd hoped for, but at least you can use it to get your foot in the door."
it means that they have got an in in the sense of opportunity ... they have made an in-road with the opportunity. It doesn't guarantee success, but progress has been made to that end.
it means that something got in the way of the the goal they're trying to achieve