Your site is functioning correctly. You must upload files into the folder public_html for you to see anything. For example, if you created a file called "test.html" and it was in the folder /home/USERNAME/public_html/ you could see it at yourdomain.com/test.html. A special case is files named index.*** will be seen without typing the file name. So, /home/USERNAME/public_html/index.php would be seen as yourdomain.com/.
I recommend using Softaculous from your CPanel to install a piece of software for you automatically. It takes very little understanding of coding to do it. Additionally, if you pick a good CMS like Drupal or Joomla!, there are literally thousands, if not more, templates to choose from to change the appearance of your site, not to mention thousands of add-ons, modules, plugins, etc to make your site do anything you want.