each of the four wheels of a car pushes on the road with a force of 4.0 x 10^3 N[down].
The driving force on the car is 8.0 x 10^3N[W]. The frictional resistance on the car
is 6.0 x 10^3N [E]. Calculate the following

a) the mass of the car
b) the net force on the car
c) the car's acceleration.

so we're given the friction force, force of the wheels pushing on the road, and the force of the car.

I'm not very sure how to start the question

please help

Start with question 1: the mass of the car. Can you see what it is? The wheels push down on the road with a certain force. Where do these forces come from? Is it related to the mass of the car? Tell us exactly what you do not understand. If you do not know what weight is, or what Newton's 2nd law is, then read your textbook first.