Hi,
Your page is c:/wamp64/www/test.php, to call it you have to type 'http://localhost/test.php'
It is absolutely not recommended to create pages in the wamp64/www/ folder which is reserved for Wampserver. You should put your pages in a folder, e.g. wamp64/www/mypages/test.php and, in this case, you will launch your page with 'http://localhost/mypages/test.php'.
The best way to do and use VirtualHost, as with all webhosts.
See :
The need for Virtual Hostand
Wampserver 3 - Create or add a VirtualHost---------------------------------------------------------------
Documentation Apache -
Documentation PHP -
Documentation MySQL -
Wampserver install files & addons