How do I edit the Default Content Layout for every new page created

1. Click on main menu item Customise
2. Then click on Site Design icon
3. And then on Layout tab
4. Here you can change the Column Layout of your website, to 2, 3 or 4 columns
5. You can also set where your Main Content, Block Content, ecommerce, Site News, Site Search and Social Media items are placed on every page
6. Save Changes