"I am going home."
Translation:Idę do domu.
“Jadę” means that you’re using a vehicle (for instance a car), “idę” means that you are on foot.
My understanding is that in the old days if you went by foot it was "isć" and if you went on a horse it was "jechać". So, when using "go" in a general way for things like "go home", "go to school", "go to the doctor's", (where people used to walk) you still use "isć", even if you are going to go by car or other form of transport.
But if someone calls you when you're in the car, tram or whatever, or you're telling somebody how you're getting home, etc, then it is "jechać".
Yes. It will either mean that you are going home on foot at the very moment you're speaking, or that you are about to leave the place you are right now and head home - Present Continuous in the (quite close) future meaning, and in this meaning you may also take a vehicle, because the important thing is that you're heading home.
Verbs of motion are among this 1% of verbs that are translated differently if they are in Present Simple and differently if they are in Present Continous. Therefore:
to go, to walk (regularly, habitually) = chodzić
to be going, to be walking (right now) = iść
to be walking (walking around, without a purpose nor direcition) = chodzić