My randomize rooms script is giving an error.

I'm creating a game of dungeons to study programming, but my script is giving an error and I can't fix it, here's my script:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class RoomSpawner : MonoBehaviour
 {
 
     public int openingDirection;
     // 1 --> need bottom door
     // 2 --> need top door
     // 3 --> need left door
     // 4 --> need right door
 
 
     private RoomTemplates templates;
     private int rand;
     public bool spawned = false;
     public float waitTime = 3.5f;
 

     void Spawn()
     {
         if (spawned == false)
         {
             if (openingDirection == 1)
             {
                 // Need to spawn a room with a BOTTOM door.
                 rand = Random.Range(0, templates.bottomRooms.Length);
                 Instantiate(templates.bottomRooms[rand], transform.position, templates.bottomRooms[rand].transform.rotation);
             }
             else if (openingDirection == 2)
             {
                 // Need to spawn a room with a TOP door.
                 rand = Random.Range(0, templates.topRooms.Length);
                 Instantiate(templates.topRooms[rand], transform.position, templates.topRooms[rand].transform.rotation);
             }
             else if (openingDirection == 3)
             {
                 // Need to spawn a room with a LEFT door.
                 rand = Random.Range(0, templates.leftRooms.Length);
                 Instantiate(templates.leftRooms[rand], transform.position, templates.leftRooms[rand].transform.rotation);
             }
             else if (openingDirection == 4)
             {
                 // Need to spawn a room with a RIGHT door.
                 rand = Random.Range(0, templates.rightRooms.Length);
                 Instantiate(templates.rightRooms[rand], transform.position, templates.rightRooms[rand].transform.rotation);
             }
             spawned = true;
         }
     }
 
     void OnTriggerEnter2D(Collider2D other)
     {
         if (other.CompareTag("SpawnPoint"))
         {
             if (other.GetComponent<RoomSpawner>().spawned == false && spawned == false)
             {
                 Instantiate(templates.closedRoom, transform.position, Quaternion.identity);
                 Destroy(gameObject);
             }
             spawned = true;
         }
     }
 }
 

and the other:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class RoomTemplates : MonoBehaviour
 {
     public GameObject[] bottomRooms;
     public GameObject[] topRooms;
     public GameObject[] leftRooms;
     public GameObject[] rightRooms;
     public GameObject[] Chest;
     public GameObject closedRoom;
     public float wait;
     public List<GameObject> rooms;
     public float waitTime;
     private bool spawnedBoss;
     public GameObject boss;
     void Update()
     {
 
         if (waitTime <= 0 && spawnedBoss == false)
         {
             for (int i = 0; i < rooms.Count; i++)
             {
                 if (i == rooms.Count - 1)
                 {
                     Instantiate(boss, rooms[i].transform.position, Quaternion.identity);
                     spawnedBoss = true;
                 }
             }
         }
         else
         {
             waitTime -= Time.deltaTime;
         }
     }
 
 
 }