The Main Menu for your site can be found at the top of every page automatically. You will not be able to modify the menu from the Elementor or page editor, it can only be done through the WordPress Dashboard Settings.

To Update the Main Menu

1. On the WordPress Dashboard, hover over Appearance then select Menus
   
2. You can drag and drop menu items in the Menu Structure section
   
3. Select the checkboxes next to any new page or content type in the Add Menu Items section