level manger and starting scene will not work together

i am trying to make a boot up scene for my game and with a float to transition to the main menu scene but the 2 scripts interfere with one a another i new to c# so i don`t how how to fix the problem if anyone can help it will be greatly appreciated ( i have stared* the problem area )

Next scene script

 using System.Collections;
 using UnityEngine;
 using UnityEngine.Video;
 using UnityEngine.SceneManagement;
 
     public class nextscene: MonoBehaviour
     {
     ** public float delay = 23;
     void Start()
     { 
         
         StartCoroutine(LoadLevelAfterDelay(delay));
     }
 
     IEnumerator LoadLevelAfterDelay(float delay)
     {
         yield return new WaitForSeconds(delay);
         SceneManager.LoadScene("MainMenu");
     }
 }

my Level Select Manager script

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class LevelSelectManager : MonoBehaviour {
 
     public string[] levelTags;
     public GameObject[] locks;
     public bool[] levelUnLocked;
 
     public int positionSelector;
     public float distanceBelowLock;
 
     public string[] levelName;
 
     public float moveSpeed;
 
     private bool isPressed;
 
     void Start(){
 
         for(int i = 0; i < levelTags.Length; i++)
         {
 
             ** if (PlayerPrefs.GetInt (levelTags [i]) == null) {
                 levelUnLocked [i] = false;
             } else if (PlayerPrefs.GetInt (levelTags [i]) == 0) {
                 levelUnLocked [i] = false;
             } else {
                 levelUnLocked [i] = true;
             }
 
             if (levelUnLocked [i]) {
                 locks [i].SetActive (false);
             }
 
         }
 
         transform.position = locks [positionSelector].transform.position + new Vector3 (0, distanceBelowLock, 0);
 
     }
 
     void Update(){
 
         if (!isPressed) {
             if (Input.GetAxis ("Horizontal") > 3.0f) {
                 positionSelector += 1;
                 isPressed = true;
             }
             if (Input.GetAxis ("Horizontal") < -3.0f) {
                 positionSelector -= 1;
                 isPressed = true;
             }
             if (positionSelector >= levelTags.Length) {
                 positionSelector = levelTags.Length;
             }
             if (positionSelector <= levelTags.Length) {
                 positionSelector = levelTags.Length;
             }
         }
         if (isPressed) {
             if (Input.GetAxis ("Horizontal") < 3f && Input.GetAxis ("Horizontal") > -3f) {
                 isPressed = false;
             }
         }
 
         transform.position = Vector3.MoveTowards (transform.position, locks [positionSelector].transform.position + new Vector3 (0, distanceBelowLock, 0), moveSpeed * Time.deltaTime);
 
     }
 }