Extract the Zip file and move the folders inside to the plugin directory. This file contains the SiteOrigin Page Builder & SiteOrigin Widget Bundle plugins since they are both used together. If you need to install it on a site you do not have FTP access to. You can download the plugins from the WordPress Marketplace.
Under Settings > Page Builder you can configure the Page Builder. Generally the default settings are acceptable. I do remove the 30px margin under each row, but this is not required.
For more information about SiteOrigin Page Builder, you can visit https://siteorigin.com/page-builder