PHP application architecture design help
I am working on a new social network type app in PHP.  I am wanting to do it all in OO and I do not want to use an existing framework.  

I have been studying many different frameworks and libraries to see how they do things like MVC.

So far what I have is something like this...

    // All request are routed through index.php
    // index.php
    
    Get requested page from URI (ie; test.com/user/friends/page-12 )
    $controller = User();
    $controller_method = friends();
    $page = 12; // for paging results
    $id = ''; //id is empty in this example but some pages will have an ID number as well

So in theory I would load a User class and friends() method.  This all sounds simple and great on a basic site but what I am building will be more complex so I am not sure exactly what  I should do next.  For example on some pages, I will require that a user is authorized already.  

So instead of loading a User class and friends method, should I be including a user friends file instead where I can have more stuff happening?

Sorry if this is confusing
PHP application architecture design help
===

I am working on a new social network type app in PHP.  I am wanting to do it all in OO and I do not want to use an existing framework.  

I have been studying many different frameworks and libraries to see how they do things like MVC.

So far what I have is something like this...

    // All request are routed through index.php
    // index.php
    
    Get requested page from URI (ie; test.com/user/friends/page-12 )
    $controller = User();
    $controller_method = friends();
    $page = 12; // for paging results
    $id = ''; //id is empty in this example but some pages will have an ID number as well

So in theory I would load a User class and friends() method.  This all sounds simple and great on a basic site but what I am building will be more complex so I am not sure exactly what  I should do next.  For example on some pages, I will require that a user is authorized already.  

So instead of loading a User class and friends method, should I be including a user friends file instead where I can have more stuff happening?

Sorry if this is confusing