I'm not a Fedora/Redhat person, so I don't really know why you don't have a graphical login screen, or what specific instructions to give you to install one. It might be an idea to post a new thread in the
fedora specific forum saying that you've installed fedora but you have no graphical login (you need to login to the console and type startx to get X running), and than TWM is the default session and you'd like something else.