Sorry but Brits would say 'at the door' rather than 'before the door'. Fair enough to accept the latter but don't mark the former as wrong!
I think it should be, as it is technically correct, but it is a little archaic. When we say "before" in modern English, it is usually a reference to time, but it can still refer to space, and would be understood. "Is this a dagger I see before me?" "The children grow up before our very eyes." And so on... But it is a little bit literary-sounding, and not as common in daily speech as it used to be.
Tor = gate; Tür = door
However, it's perfectly fine to say "steht das Auto vor deiner Tür?" even if you mean the garden gate.
I do not understand how Steht works here. Is it past tense? Or can I say "Ich Stehe das Auto", I park the car, or "Stehe ich das Auto?" Should I park the car?
Steht is the verb, the action of the sentence. You can't replace it by a pronoun, just as you don't replace "is...parked" with "it" for no reason.
You are correct, but DL gives one of the correct responses as "is the car in front of your gate"
The noted translation for the "steht" is "stands" I have never heard that a car stands somewhere. In this context one more meaningful translation for the verb stehen is to stop.
But to stop would be the act of arriving and then halting. Stehen just means it is parking there, maybe for decades already. I don't think you should translated that with to stop.
One of the correct answers provided has Parked. Then why is the German phrase Steht and not Stand?
I am confused by this translation. I would have thought that the German for, "Is the car parked in front of your gate" would be, "Ist das Auto vor deinem Tor geparkt?". In the USA, there is a distinction between a car that is stopped (the engine is on and the driver is at the wheel), standing (the engine is off and the driver is at the wheel) and a car that is parked (the engine is off and the driver is not at the wheel). Is there such a distinction in German or do stehen and parken mean exactly the same thing when applied to an auto?