Can't reach the website after WordPress installation

Hello everyone, I am trying to add a new child domain under the main one. Even though the Wordpress installation succeeds, I am not able to reach the website. Can anyone help me with this?

I know that this is an old topic, but I just had the same problem. So, here’s how I solved it, in case someone comes across this.
Open your wp-config.php file, and right below the PHP opening tag, add:
define( ‘WP_CACHE’, true );

show me exact error?