How do I destory the enemy and item so they don't respwan after reload the scene.

I am stuck on this for 2 days now, can anyone help me please. I am making a grid base dungeon explore game. The issue is when the player go to the next floor ( trigger next scene) and come back, all the enemies and items reappear in the scene. I was able to get my player stats working by using a static class, but I can't do that for the enemy or pickup because some of them share the same script. What I tried so far is to store each gameobject in the hierarchy into a list to get their name, then assign a bool list to get the current status. So right now I am able to get all the game object that tag with the enemy on the console, and it does output a debug message that tells if the enemy should be destroy on the next load. I tried to set active(false) of the list or destroy the gameobejct in the list, both don't work. What should I do next? Below is what my game looks like and script.

using UnityEngine;

using System.Collections;

using System.Collections.Generic;

public class destroyonload : MonoBehaviour { // Start is called before the first frame update public static destroyonload instance;

 public static List<GameObject> mylist = new List<GameObject>();
 List<GameObject> list1= new List<GameObject>();
 public static List<bool> boollist = new List<bool>();
 public static List<GameObject> itemlist;

 void Awake()
 {
     DontDestroyOnLoad(this);

     if(instance == null)
     {
         instance = this;
     }

      else
     {
       //Duplicate GameManager created every time the scene is loaded
       
       Destroy(gameObject);
     }       
     
     foreach (GameObject obj in Object.FindObjectsOfType(typeof(GameObject)))
         {     
             //obj.CompareTag("canbepickup")||
             if(obj.CompareTag("enemy")){
                 Debug.Log(obj.name);
                 list1.Add(obj);
                     if(Enemy.shoulddestroy == false){
                     Debug.Log("First time encounter" + obj);
                     boollist.Add(false);
                 }

                 else{
                     Debug.Log("the hit object should be destory" + obj);
                     boollist.Add(true);
                 }
                 //array2.AddRange(list1,boollist);
             }
         }

     itemlist.AddRange(list1);
 }

 void Start()
 {
     if(itemlist!= null)
     {
         foreach(GameObject list in mylist){
             Debug.Log("attempt to destory list" + list);

             if(list.activeInHierarchy){
             list.SetActive(false);
             Debug.Log("attempt to set active false");
             }

             Debug.Log("done destory");
         }
         
         int i = 0;
         while(itemlist[i]!= null){

                 int j =0;
                 for(j=i;j<itemlist.Count;j++)
                 {
                     if(boollist[j] ==true){
                         Destroy(itemlist[i]);
                     }
                 }
                 i=i+1;
         }
         
             
         
     }
     
     
 }

}

Enemy Script:

using System.Collections;

using System.Collections.Generic;

using UnityEngine;

public class Enemy : Character {

 public static bool shoulddestroy= false;

 public int damageStrength;

 void OnTriggerEnter2D(Collider2D other)
 {
     if (other.gameObject.CompareTag("Player")){
         shoulddestroy = true;
         print("you should destory on next load"+ other.gameObject);
     }
         
 }

 void OnTriggerExit2D(Collider2D other)
 {
     if (other.gameObject.CompareTag("Player")){
         
         print("im out"+ other.gameObject);
     }
         
 }