samba isn't a GUI application, it consists of two programs that run in the background called smbd and nmbd. In linux background programs are known as daemons. These daemons in a nutshell let linux PCs share files and printers with windows PCs.
I have never used fluxbox so I don't know if it is configured like KDE and Gnome with system settings GUIs. From a console window you can start samba:
service smb start
for details on samba.
So what is the real question?