Displacement is the vector - arrow connecting the current position of the body with the origin or initial position. It tells how far we are / the body is from the initial position and it tells also about in which direction the body is. It depends on the current position.
Velocity: It is the rate of change of position, displacement in time. means how fast the distance from origin, initial position is changing. This is also a vector and its direction is the change of displacement. In other words, the vector connecting final position and initial position will give the direction of velocity.
Acceleration: One may travel with uniform speed, it is easy to understand. But when I start a vehicle and travel with a speed of 40 kmph, there is a duration of increase of speed from 0 to 40kmph. This is caused by the Force/torque supplied by the engine. Due to the force/torque an acceleration is generated, that is the rate of change of velocity.
Acceleration is in the direction of change of velocity. When a vehicle is going north from south and is slowing down, velocity is towards North and acceleration is in direction of South