PHYSICS (action and reaction)

Note that by Newton's third law of motion, an action and reaction pair are equal in direction but opposite in direction, they act on two and only two bodies.

So to speak, that when an action force is acting on one object A by the other object B, then there must be a reaction force acting on B by A.

Therefore, for your case, when you push the car, the car accelerates due to a net force acting on it.

The car will exert a reaction force on YOU. But not on itself. The reaction force is same in magnitude as the action, but opposite in direction.

Therefore, the net force on the car is not zero.