I realise, the question was asked two years ago. Still, someone may have the same Q.
This is a very broad question. Modern webpages are dynamically created. This means the content is in a database. The user makes a request to see something. The request goes to a (php) page that makes decisions what to create: is it a new or known user, is there history to the user, is it a member ... which part of the site the request is targetting ... what banner needs to be displayed, what language, which sponsors/advertisers will be displayed - if any - you continue the list.
When all is decided, the page will be created on the fly.
This is a CONTENT MANAGEMENT SYSTEM or CMS.
You need to design the structure of the system, then code it.
Or get an off-the-self one like Drupal or others.
If you design it, you have full control and it will be EXACTLY what you want. You can fully control security. With off-the-shelf systems this is unlikely. Many has huge security issues.
Cheers,
Bill