Can't enable canvas

I can't seem to enable a Canvas what so ever. I watched a video(more than 10 times) and followed everything EXACTLY. And I ended up with this script. The Canvas.enable = false; and Canvas.enable = true; does not seem to be functioning.

 using UnityEngine;
 using UnityEngine.UI;
 using System.Collections;
 
 public class PauseMenu : MonoBehaviour 
 {
     public Canvas pausemenu;
     public Button pause;
     public Button restart;
     public Button cont;
     public Button quit;
     public Button mainMenu;
     
     void Start()
     {
         pausemenu = pausemenu.GetComponent<Canvas> ();
         pause = pause.GetComponent<Button>();
         restart = restart.GetComponent<Button> ();
         cont = cont.GetComponent<Button> ();
         quit = quit.GetComponent<Button> ();
         mainMenu = mainMenu.GetComponent<Button> ();
         pausemenu.enabled = false;
     }
 
     public void PauseGame()
     {
         pausemenu.enabled = true;
     }
 }