X is a graphical server, you will need a GUI to go with it as well, in linux everything for the most part is setup as a modular client-server type arrangement, graphics is no different, X provides a graphics server and the GUI passes commands to it-------KDE,Gnome,xfce,blackbox,fluxbox,icewm are some of the popular GUI's you can install
it should have xorg or xf86 on the install disk, if not it either can be found easily, check the package list or README or index on your install disk, somewhere it should have a list of whats on it
you will also likely have to setup the sound as well, probably have to install ALSA and possibly recompile the kernel for sound as well, Ive never done a freeBSD install since the 4 series, hardware support with any of the BSD's can be tough to deal with for newbies