Facebook registration plugin

CSU

If anyone could kindly nudge me in the correct direction I'd be greatly appreciate it.

The sheer amount of (outdated) info on facebook-connect and methods that are no longer standard is mind-boggling, simply what I want to do is:

From my website --> ask user to register/connect with FB account --> INSERT username and email into my MySQL schema...

The Facebook Registration Plugin claims to do this but goes as far as issuing a "signed_request" and any or all of the info out there talks of "connect Url's" in the app CP which are n0 longer there?

For example, here's a tutorial titled 'How to Authenticate Users With Facebook Connect' from Jun 10th 2010

I fail at the first hurdle
[PHP]<?php
# We require the library
require("facebook.php");

# Creating the facebook object
$facebook = new Facebook(array(
'appId' => 'YOUR_APP_ID',
'secret' => 'YOUR_APP_SECRET',
'cookie' => true
));

# Let's see if we have an active session
$session = $facebook->getSession();

if(!empty($session)) {
# Active session, let's try getting the user id (getUser()) and user info (api->('/me'))
try{
$uid = $facebook->getUser();
$user = $facebook->api('/me');
} catch (Exception $e){}

if(!empty($user)){
# User info ok? Let's print it (Here we will be adding the login and registering routines)
print_r($user);
} else {
# For testing purposes, if there was an error, let's kill the script
die("There was an error.");
}
} else {
# There's no active session, let's generate one
$login_url = $facebook->getLoginUrl();
header("Location: ".$login_url);
}
?>
[/PHP]
...nothing but blank page - I can't even find where to enter connect Url in app CP.