Most Joomla templates display the site name defined in the Joomla configuration file configuration.php. Usually, the site name is set as the domain name for your website.

In order to hide it, you need to delete the domain name and save the configuration with a blank site name. For example, if your domain name is mysite.com, in your configuration.php file you will have this line:

var $sitename = 'mysite.com';

To hide the site name, you need to change the above line to:

var $sitename = '';