?port 80 is for serving web pages. www.domain.com is served on port 80. You will see nothing unless you have an account setup and dns resolved, etc etc. It sounds like you are setup properly. Create an account, upload a site and off you go.
A common issue is where people see a cached version of the page: try clearing your internet browsers cache and reload. Sounds like the DNS is fine, but if you've recently changed the site it can take time. Try entering the domain name without the "www." in front of it, since that takes less time to propagate (think it has something to do with cPanel setting up the www as a cname by default).