1) The error:
"The URL prefix "/serving/" of your testing server does not match the URL prefix
"/"of your site."
there are 2 places to enter the site URL:
On the general tab of the site settings, and on the Testing server tab.
This error is saying that address on the general tab does not match the one on the testing server tab, and because you have site relative links enabled, this will be an issue
2) your path for site files:
using an upper case S for the folder name.
apache is case sensitive, so the address must match that case:
3) This error:
Fatal error: php_network_getaddresses: getaddrinfo failed: No such host is known. in C:\xampp\htdocs\Serving\Connections\serving.php on line 9"
means the host name entered in the connection file is not correct.
using the localhost testing server, the host name should be:
also make sure the MySQL Service has been launched in the xampp control panel.