so if i used the css i could make a forum that i can add stuff.Just like a normal one with my own domain name and what not?
see above replies.
When you say "add stuff" what do you mean? Add features or add content? If you want to add features you will need to code it in whatever server-side language you choose to author in.
Domain names are a different story altogether. You will need to buy one and assign it to your server space (assuming you have some). If you do not you will need to buy some server space from a web host. Most of these will/can provide a domain name for you. I use and recommend ipowerweb.com. I'd check it out, they have a lot of built in features, even bulletin boards.