Camera script does not work for different scene

Hello. I copied a code for a 3D godlike view from a youtube tutorial for simulation games cameras. The code seemed to work well in the scene I wrote the code (i.e. all the settings for the camera were working as intended). However, when I try to copy the camera rig (which is an empty object including the camera and the camera settings codes such as moving forward with W key) into a different scene, it does not work at all. I am new to unity so I do not understand how can I implement a camera or any other code that I wrote from a scene to another. Thanks in advance.

Here's the original code:

using System.Collections;

using System.Collections.Generic;

using UnityEngine;

public class CameraController : MonoBehaviour {

public Transform cameraTransform;

 public float normalSpeed;
 public float fastSpeed;

 public float movementSpeed;
 public float movementTime;
 public float rotationAmount;
 public Vector3 zoomAmount;

 public Vector3 newPosition;
 public Vector3 newZoom;
 public Quaternion newRotation;

 public Vector3 dragStartPosition;
 public Vector3 dragCurrentPosition;
 public Vector3 rotateStartPosition;
 public Vector3 rotateCurrentPosition;

 
 // Start is called before the first frame update
 void Start()
 {

     newPosition = transform.position;
     newRotation = transform.rotation;
     newZoom = cameraTransform.localPosition;

 }

 // Update is called once per frame
 void Update()
 {
     HandleMouseInput();
     HandleMovementInput();
 }

 void HandleMouseInput()
 {
     if(Input.mouseScrollDelta.y != 0)
     {
         newZoom += Input.mouseScrollDelta.y * zoomAmount;
     }

     if (Input.GetMouseButtonDown(0))
     {
         Plane plane = new Plane(Vector3.up, Vector3.zero);

         Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);

         float entry;

         if(plane.Raycast(ray, out entry))
         {
             dragStartPosition = ray.GetPoint(entry);
         }
     }
     if (Input.GetMouseButton(0))
     {
         Plane plane = new Plane(Vector3.up, Vector3.zero);

         Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);

         float entry;

         if (plane.Raycast(ray, out entry))
         {
             dragCurrentPosition = ray.GetPoint(entry);

             newPosition = transform.position + dragStartPosition - dragCurrentPosition;
         }
     }

     if (Input.GetMouseButtonDown(2))
     {
         rotateStartPosition = Input.mousePosition;
     }
     if (Input.GetMouseButton(2))
     {
         rotateCurrentPosition = Input.mousePosition;

         Vector3 difference = rotateStartPosition - rotateCurrentPosition;

         rotateStartPosition = rotateCurrentPosition;

         newRotation *= Quaternion.Euler(Vector3.up * (-difference.x / 5f));
     }
 }

 void HandleMovementInput()
 {

     if (Input.GetKey(KeyCode.LeftShift))
     {
         movementSpeed = fastSpeed;
     }
     else
     {
         movementSpeed = normalSpeed;
     }

     if (Input.GetKey(KeyCode.W) || Input.GetKey(KeyCode.UpArrow))
     {
         newPosition += (transform.forward * movementSpeed);
     }
     if (Input.GetKey(KeyCode.S) || Input.GetKey(KeyCode.DownArrow))
     {
         newPosition += (transform.forward * -movementSpeed);
     }
     if (Input.GetKey(KeyCode.D) || Input.GetKey(KeyCode.RightArrow))
     {
         newPosition += (transform.right * movementSpeed);
     }
     if (Input.GetKey(KeyCode.A) || Input.GetKey(KeyCode.LeftArrow))
     {
         newPosition += (transform.right * -movementSpeed);
     }

     if (Input.GetKey(KeyCode.Q))
     {
         newRotation *= Quaternion.Euler(Vector3.up * rotationAmount);
     }
     if (Input.GetKey(KeyCode.E))
     {
         newRotation *= Quaternion.Euler(Vector3.up * -rotationAmount);
     }
     if (Input.GetKey(KeyCode.R))
     {
         newZoom += zoomAmount;
     }
     if (Input.GetKey(KeyCode.F))
     {
         newZoom -= zoomAmount;
     }

     transform.position = Vector3.Lerp(transform.position, newPosition, Time.deltaTime * movementTime);
     transform.rotation = Quaternion.Lerp(transform.rotation, newRotation, Time.deltaTime * movementTime);
     cameraTransform.localPosition = Vector3.Lerp(cameraTransform.localPosition, newZoom, Time.deltaTime * movementTime);
 }

}