Maybe you have not run the eZ installation process properly. When you have installed eZ Publish, you see the welcome page in your webbrowser. When you follow the steps on the page, you can choose which modules you want to install, "intranet" or "corporate" for example. When I remember correctly, we choose "intranet" an then we found the "plain" and "plain_admin" folders in "settings/siteaccess/"
