c# – cannot implicitly convert type “void” to “UnityEngine.Vector2”

I am new to C# and have not used Unity that long. I am trying to have a projectile fire at my pointer, but it is firing closer to the base of my pointer. I have tried normalizing it by making a player, but I now keep getting this error and cannot find anything online that can help me

    private Rigidbody2D Player;
    public Rigidbody2D BallPrefab;
    public float attackSpeed = 0.5f;
    public float projectileSpeed = 500;

    void Fire() {
        Player = GetComponent<Rigidbody2D>(); 
        Vector2 mousePosition = Camera.main.ScreenToWorldPoint(Input.mousePosition);
        Vector2 playerPosition = Player.transform.LookAt(Input.mousePosition);
        Vector2 shootDirection = (mousePosition - playerPosition).normalized;

        Rigidbody2D ball = Instantiate(BallPrefab, new Vector2(transform.position.x, transform.position.y),
      transform.rotation) as Rigidbody2D;
        

      ball.GetComponent<Rigidbody2D>().AddForce(shootDirection);
      Debug.Log(mousePosition);
    }

I have been trying to make a playerPosition, but after half an hour of trying different things, I can not figure out what is going wrong.