You can add a sidebar to any page in the page settings. You can also add columns.

Step 1

Go to the Pages tab.

Step 2

Click on the settings (gear) icon next to the page you want to add a sidebar to.

Step 3

Next to Content section, indicate whether you want to add a sidebar to this page.

Step 4

Click on Save to add the sidebar.

 Note: Sidebars can only be used with certain Designs.