Do I need a helper class?

So I don't know what a helper class is or at least I don't know how to use one in Unity3D.

I'm trying to get TouchInputHelper.cs to clean up my code. I will be using it to handle all the things I might need to do with touches. I don't want to be rewriting code in different classes so I thought I could just put my needed functions into my TouchInputHelper.cs and start using that in other classes. I don't really know the term for what I'm trying to do.

I have a ShipRotation.cs and a DragMove.cs which both use a method I wrote that will take a Victor2 and convert it into a world point. Right now it's just test code to get these two classes talking to TouchInputHelper.cs but it doesn't seem to be working and I don't know what I'm doing wrong.

 public class ShipRotation : MonoBehaviour
 {
     ShipControls _shipControls;
     public GameObject ship;
     TouchInputHelper touchInputHelper;//Adding it here so I can use this classes functions
 
     // Use this for initialization
     void Start()
     {
         _shipControls = GetComponent<ShipControls>();
     }
 
     RaycastHit hit;
     public LayerMask touchInputMask;
     Vector3 target;
     void Update()
     {
         //ship.transform.Rotate(Vector3.right * Time.deltaTime);
         if (Input.touchCount > 0)
         {
             foreach (Touch touch in Input.touches)
             {
                 Ray ray = Camera.main.ScreenPointToRay(touch.position);
 
                 if (Physics.Raycast(ray, out hit, touchInputMask))
                     
                 {
                     GameObject recipient = hit.transform.gameObject;
                     if (recipient.tag == "Player")
                     {
                         //I'm not sure if this line is working
                         target = touchInputHelper.turnTouchInputToWorldPoint(new Vector2(touch.position.x, touch.position.y));                    
                 }
             }
         }
         ship.transform.LookAt(target);
     }    
     public float damping = 10f;
 }

Here is what I'm trying to use as a helper class. It is only written with test code right now.

 using UnityEngine;
 using System.Collections;
 
 public class TouchInputHelper : MonoBehaviour{
     bool usingTouch = true;
     Vector3 gameObjectToScreenPoint;
     public string hello= "test";
 
     public Vector3 turnTouchInputToWorldPoint(Vector2 v2)
     {
         Vector3 v3;
         if (usingTouch)
         {
             v3 = new Vector3(v2.x, v2.y, gameObjectToScreenPoint.z);
         }
         else
         {
             v3 = new Vector3(1, 1, 10);
             //v3 = new Vector3(Input.mousePosition.x, Input.mousePosition.y, gameObjectToScreenPoint.z);
         }
         return v3;
     }
 }

What am I doing wrong? Do I need to add TouchInputHelper.cs as a component then use GameObject.Find to use it?