Set proxy authentication information in Fiddler

Tools menu -> Fiddler Options -> Connections tab -> Fiddler listens on port

There you can change the port that Fiddler uses.

In Fiddler, select the Inspectors tab to see the Request and Response. Now, this tab is split horizontally; the Request Inspectors are across the top, and the Response Inspectors are across the bottom. If you don't see the tabs along the bottom, grab the blue splitter line near the bottom and drag it upward. If you don't see even that, restart Fiddler while holding the SHIFT key to reset the UI to its default layout.