Game starts with pause menu activated

that's it. I used this tutorial https://www.youtube.com/watch?v=JivuXdrIHK0 to make a pause menu, but when I test the game the program starts in the pause menu, also locks the mouse movement so I can't press any button. what could be missing?

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class MenuPausa : MonoBehaviour
 {
     public static bool GameIsPaused = false;
 
     public GameObject pauseMenuUI;
 
 
     void Update()
     {
         if (Input.GetKeyDown(KeyCode.Escape))
         {
             if (GameIsPaused)
             {
                 Resume();
             }
 
             else
             {
                 Pause();
             }
         }
     }
     public void Resume()
     {
         pauseMenuUI.SetActive(false);
         Time.timeScale = 1f;
         GameIsPaused = false;
     }
 
     void Pause()
     {
         pauseMenuUI.SetActive(true);
         Time.timeScale = 0f;
         GameIsPaused = true;
     }
 
     public void LoadMenu ()
     {
         Debug.Log("Loading menu...");
     }
 
     public void QuitGame()
     {
         Debug.Log("Quitting game...");
         Application.Quit();
     }
 }