How do I make a main menu item jump to the first sub menu item

 

    
1.  Click on Customise in the main menu.    2. Click on Site Content.
     
 
3. Under Home Page, Inner page and Information Pages, hover over the webpage you wish to edit.   4. Then click the Page Settings icon
     
 
5. Under Menus on the right hand side, click on the radio button which says Jump to first sub menu item   6. Save Changes