Yes, your understanding is correct.
a) The net force on the car is not zero because it is experiencing a centripetal force. This force is directed towards the center of the turn and provides the necessary inward acceleration for the car to follow the curved path.
b) The velocity of the car is not constant because it is constantly changing its direction. Velocity is a vector quantity that includes both magnitude (speed) and direction. As the car turns, its direction changes, resulting in a change in velocity.
c) Since the velocity of the car is changing, it is experiencing acceleration. Acceleration is the rate at which velocity changes over time. In this case, the car is accelerating towards the center of the turn due to the centripetal force, which constantly changes its direction and magnitude of velocity.
Overall, your explanations are spot on! Good job in understanding the concepts of forces, velocity, and acceleration in the context of a car making a turn.