What is the difference between acceleration, speed and velocity?

Answer 1

acceleration and velocity are vectors. They have magnitude and direction.
In your car, speedometer gives speed but you need a speedometer AND a compass for velocity
acceleration is the rate of change of velocity. If you go in a circle at constant speed your velocity changes and you experience centripetal acceleration.

You did not ask yet but distance is a scalar and displacement is a vector with distance AND direction. If you go all the way around a circle your distance is 2 pi R but your displacement is ZERO