How do i check if php server allows external curl connections
You'll definitely need to buy an account before testing the server's capacities.
But some hosts allow you to test their site with a monthly contract or a XX days money back guarantee. From the top of my head, Host gator is such host.
Then when you have that account, try a small script like this (check the path to curl with your host helpdesk or documentation):
<?php$var = echo shell_exec("/usr/bin/curl -L http://www.google.com");?>