All your website's files and folders should be placed under the public_html directory in your cPanel. Please be sure to create an index file for your first page, this can be index.htm, index.html, index.php, etc. Our system looks for those exact names by default and it must be placed directly under public_html and not a subfolder. When you go to http://yourdomain.com, this file will then automatically open, without it your file structure will show instead.
For subdomains and other folders, when going to the folders at http://sub.yourdomain.com or http://yourdomain.com/folder/ an index file in them will behave the same way and automatically open