can you tell me where is my fuel pump?

Its in the fuel tanker.

Can you tell me what the problem is? :? :? I have to keep my foot on the gas and the brakes just a little when I am at a stop light or when stopping or the car will turn off. The car makes a humming sound when I start the car and when I am driving.

Stalling could be caused by the idle air control valve and a crack open EGR. Check fuel pressure. Humming where is coming from? underneath or engine compartment

the noise is coming from underneath the car.

What make you asked where's the fuel pump-could be it-if the noise is more towards the back.