What are you expecting? The default Tomcat homepage? If so, you’ll need to configure Eclipse to take control over from Tomcat.
Doubleclick the Tomcat server entry in the Servers tab, you’ll get the server configuration. At the left column, under Server Locations, select Use Tomcat installation. This way Eclipse will take full control over Tomcat, this way you’ll also be able to access the default Tomcat homepage with the Tomcat Manager when running from inside Eclipse. I only don’t see how that’s useful while developing using Eclipse.
Note, when it is grayed out, read the section leading text! It literally says “Server must be published with no modules present to make changes”. In other words, make sure that you’ve removed all modules via rightclick server and Add and remove… option, and then performed rightclick server and Publish.
The port number is not the problem. You would otherwise have gotten an exception in Tomcat’s startup log, and the browser would show a browser-specific “Connection timed out” error page and thus not a Tomcat-specific error page which could impossibly be served when Tomcat was not up and running.