You buy a domain name from a domain registrar like godaddy.
Then you find a web host, and for what you want you're better off getting a paid web host, though there are some free ones that may give you the flexibility you need. I don't recomment godaddy for what you're trying to do.
After that, all you have to do is construct your pages and upload them to your site with FTP.
You can install anything you want (including your wordpress blog) anywhere you want on your site and just link to it. Many webhosts have easy install for blogs, forums, etc.
Then you find a web host, and for what you want you're better off getting a paid web host, though there are some free ones that may give you the flexibility you need. I don't recomment godaddy for what you're trying to do.
After that, all you have to do is construct your pages and upload them to your site with FTP.
You can install anything you want (including your wordpress blog) anywhere you want on your site and just link to it. Many webhosts have easy install for blogs, forums, etc.