2D pong game. HELP

Hi I’m new to Unity 3D and I’m trying to make a pong game.
equal to the image.
http://gamefroot.com/wp-content/files/2012/06/pongpic.png

My questions are:

  1. How do I get the ball never stops moving

  2. That leaves the ball in different directions when the game starts

Thank you for your help

  1. Set the velocity to something specific in FixedUpdate():

    function FixedUpdate() {
    rigidbody2D.velocity = rigidbody2D.velocity.normalized * speed;
    }

  2. Pick a random initial direction for the ball:

    rigidbody2D.velocity = Quaternion.AngleAxis(Random.Range(0,360), Vector3.forward) * Vector3.up * speed;