Trying to get a 2D RayCast to instantiate a GameObject

Hi everyone, as the title suggests, I've been trying to create a 2d RayCast. I'm fairly new to C# and Unity as a whole, so I'm probably missing something fairly simple to see!

I want this raycast to detect shootable layers that I define. Firstly, the Debug.DrawRay doesn't show anything, secondly, the shoot method doesn't perform, nor does it show the Debug.Log message I placed within.

 using UnityEngine;
 using System.Collections;
 
 public class ProjectileSystem : MonoBehaviour {
     //SUMMARY
     //These array lists can be added to as the game progresses. 
     //This array list allows for a neat and tidy code structure without dumping too many
     //unneccesary lines of code for float declarations.
     //
     //
     //Declaring an open array list for various ranged projectiles.
     public int[] projectileDamage = new int[] { 15, 20 };
     //Declaring an open array list for float timers between allowed shot projectiles
     public float[] timeBetweenShots = new float[] { 0.5f, 0.6f, 2f };
     //Declaring an open array list for range of various projectiles
     public float[] rangeForShots = new float[] { 45f, 60f };
 
     public GameObject arrow;
     public float speed;
 
 
     //Private declaration list
     float timer;
     Ray2D projectileRay;
     RaycastHit2D projectileHit;
     int shootableMask;
 
 
     // Use this for initialization
     void Awake () {
         shootableMask = LayerMask.GetMask("Shootable");
     }
     
     // Update is called once per frame
     void Update () {
         timer += Time.deltaTime;
         //We'll start with the basic arrow array first.
         if (Input.GetButton("Fire1") && timer >= timeBetweenShots[0])
         {
             Shoot();
         }
     }
 
     void Shoot()
     {
         timer = 0f;
 
         //TODO
         //Add in instantiation of arrow projectile sprite
          
 
         projectileRay.origin = transform.position;
         projectileRay.direction = transform.forward;
 
         if(Physics2D.Raycast (projectileRay.origin, projectileRay.direction, rangeForShots[1], shootableMask))
         {
             Instantiate(arrow, transform.position, Quaternion.LookRotation(projectileRay.direction));
             Debug.DrawRay(transform.position, projectileRay.direction, Color.green);
         }
     }
 }
 

How would I go about getting the 2D raycasts to show, and also to instantiate an object based off of the start position and following through with the direction?

Many thanks in advance!