1) You need a domain (name, such as mywebsite.com) that nobody is using
2) You need a hoster (their computers will "host" your web site
3) You need to create the pages
You can go to godaddy.com and they can do all of this for you.
1) They have a place where they can check to see if the domain you want is available
2) They do hosting
3) They have software which will allow you to create the pages. They might not look as "cool" as a site like this, but they'll be decent.
When it comes to paying, there will actually be two separate charges. You will get charged a monthly service fee (but probably pay it by the year) for the hosting, then you actually have to pay to "own" your domain name. That must get registered with the internet (somewhere), but godaddy can/will do it for you.
I use godaddy, and have been satisfied with them. There is also a competitor, that might be a little cheaper a buddy told me about, called host gator:
Also.... I know back in the day there used to be FREE web hosting sites. You'd go there, and setup your site. The only thing with that, is you don't get to have your own domain. Instead, it would be something like:
If you don't mind that, then just google around for "free web hosting" or something like that.