There are two ways to enable error reporting in your PHP scripts.
1. You can add the following function in the .php file for which you would like the error reporting enabled:
error_reporting(E_ALL);
2. You can add the following option in the php.ini file for your web site:
error_reporting = E_ALL
Those will enable reporting for all PHP errors. The detailed error_report documentation and various options you can set can be found in the official PHP documentation at:
http://php.net/error-reporting
At SiteGround PHP error reporting is enabled by default for all hosting accounts.