An initial page, at the top level of your site structure, is the page that will be displayed when users access the root of your website (that is, they do not request any particular page from your site). If you're specifying an initial page for a folder, this page will be used for a similar purpose.
You can set the front page for your site in the page configuration, by navigating to the page you want to set as your front page. Click the cubes icon in the upper right corner of your screen to switch to Structure Editing mode. Click the configure button at the top of your page, and click the button to set as front at the bottom of the configuration screen. See this guide for help with accessing your page configuration.
Note:
1. Your site front page can't be added to a folder. If the front page you want to use is added to a folder within your site, you'll need to move this out as a separate navigation item.
2. You cannot use a single link page as the front page, since this is a link and does not have a page of its own.
3. The page you use must be enabled to display as your front page, see Step 5 of this guide.