There is nothing in this code that indicates it will shoot anything. Move, rotate, ignore Jump, that's all.

First of all, bulletPrefab is your bullet prefab, it needs to be declared as GameObject. Then in your character control script, you need to do so when your mouse is clicked. It will instantiate a bullet prefab in correct direction. See below:

var bulletPrefab:GameObject;
var speed = 3.0;
var rotateSpeed = 3.0;

function Update ()
{ 
    var controller : CharacterController=GetComponent(CharacterController);

    var forward = transform.TransformDirection(Vector3.forward);
    var curSpeed = speed * Input.GetAxis ("Vertical");

    controller.SimpleMove(forward * curSpeed);
    transform.Rotate(0, Input.GetAxis ("Horizontal") * rotateSpeed, 0);

    if(Input.GetButtonDown("Jump"))
    //put your jump function below
    print("I jumped!");

    if(Input.GetButtonDown("Shoot"))
    Instantiate(bulletPrefab,transform.posistion,Quaternion.FromToRotation(transform.posistion, forward );
}   

You also need to create a script to control movement of your bullet. Put below on your bullet prefab:

var speed = 3.0;

function Update(){
 transform.Translate(Vector3.up *speed* Time.deltaTime, Space.World);
}

That's basically the idea how to shoot a bullet out.