Besides the standard pages with horizontal header, you can create pages with side panel in Polo theme. The example of such page is Polo Architect layout. To get started create a new page, scroll down to Page options and choose side panel option under Header options tab.
Below there appear options to customize contents of the side panel.
Upon customization of the side panel, begin adding content to your page. If you want to have side panel on every page of your site, enable it from Theme options>Header options section.