"Invalid argument"?

Brand new to this stuff so excuse any horrible-ness

So I've been following tutorials on Unity 2d and I've watched the official 2d character controller

and brackey's shooting tutorial part 1 & 2

These two seem to conflict so I'll post both scripts and if you can help in any way that'd be greatly appriciated

First one is unity

public float maxSpeed = 10f; bool facingRight = true;

 Animator anim; 

 bool grounded = false; 
 public Transform groundCheck;
 float groundRadius = 0.2f; 
 public LayerMask whatIsGround; 
 public float JumpForce = 700f;

 void Start ()
 {
     anim = GetComponent<Animator> ();
 }
 
 void FixedUpdate () 
 {
     grounded = Physics2D.OverlapCircle (groundCheck.position, groundRadius, whatIsGround);
     anim.SetBool ("Ground", grounded);

     anim.SetFloat ("vSpeed", GetComponent<Rigidbody2D>().velocity.y); 

     float move = Input.GetAxis ("Horizontal");

     anim.SetFloat ("Speed", Mathf.Abs (move));

     GetComponent<Rigidbody2D>().velocity = new Vector2 (move * maxSpeed, GetComponent<Rigidbody2D>().velocity.y); 

         if(move > 0 &&!facingRight)
             Flip ();
         else if(move < 0 && facingRight)
             Flip ();
 }

 void Update()
 {
     if (grounded && Input.GetKeyDown (KeyCode.Space)) 
     {
         anim.SetBool ("Ground", false);
         GetComponent<Rigidbody2D>().AddForce(new Vector2(0, JumpForce)); 
     }
 }

 void Flip ()
 {
     facingRight = !facingRight;    
     Vector3 theScale = transform.localScale;
     theScale.x *=-1;
     transform.localScale = theScale;
 }

}

and this is Brackey's script

 public float fireRate = 0;
 public float Damage = 10;
 public LayerMask whatToHit;

 float timeToFire = 0;
 Transform firePoint;

 void Awake () {
     firePoint = transform.FindChild ("firePoint");
     if (firePoint == null) {
         Debug.LogError ("No firePoint? WHAT?!");
     }
 }
 
 // Update is called once per frame
 void Update () {
     
     Shoot ();

     if (fireRate == 0) {
         if (Input.GetButtonDown (Fire1)) {
             Shoot ();
         }
     } 
     else {
         if (Input.GetButton ("Fire1") && Time.time > timeToFire) {
             timeToFire = Time.time + 1 / fireRate;
                 Shoot ();
         }
     }
 }

 void Shoot ()
 {
     Vector2 mousePosition = new Vector2 (Camera.main.ScreenToWorldPoint (Input.mousePosition).x, Camera.main.ScreenToWorldPoint (Input.mousePosition).y);
     Vector2 firePointPosition = new Vector2 (firePoint.position.x, firePoint.position.y);
     RaycastHit2D hit = Physics2D.Raycast (firePointPosition, mousePosition - firePointPosition, 100, whatToHit); 
     Debug.DrawLine (firePointPosition, (mousePosition - firePointPosition) * 100, Color.cyan);
     if (hit.collider != null) { 
         Debug.DrawLine (firePointPosition, hit.point, Color.red);
         Debug.Log ("We hit" + hit.collider.name + "and did" + Damage + " damage."); 
     }
 }

}