HTML is the language that tells the web browser how to render the page, there is no other way around it. On the front end there will be HTML, CSS, and JavaScript (possibly with the jQuery library) and on the back end you will need something like PHP, Perl, Ruby, and/or Python.
HTML renders the page, CSS described the page, and Javascript makes the front end dynamic. The back end languages make the page persistent, and help to store information, and change the display based on stored information.
If all you are wanting to do is set up a pre-made social networking site, even simple forum boards need at least something like Wordpress, which still requires a bit of knowledge of all the other stuff.