projetrunandgun/Assets/MainMenu.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;

public class MainMenu : MonoBehaviour {

    public string levelToLoad;

    public GameObject settingPanel;
    public GameObject gameName;
    public void StartGame()
    {
        SceneManager.LoadScene(levelToLoad);
        Time.timeScale = 1;
    }

    public void SettingsOpen()
    {
        settingPanel.SetActive(true);
        gameName.SetActive(false);
    }

    public void SettingsClose()
    { 
        settingPanel.SetActive(false); 
        gameName.SetActive(true);
    }
    public void QuitGame()
    {
        Application.Quit();
    }
}