1) Choose either pppconf or vwdial, don't use both as they're two different ways of doing the job. Pick up your favourite; I like wvdial because it's straightforward to configure (just edit wvdial.conf found in /etc/ if I'm right; fill in the needed information, save and run wvdial). If you use pppconf, then you should probably use 'pon' to connect (and 'poff' to disconnect).
2) Usually if a command does not print output it means "good". Typically output is given if there's some information the program wants to give to the user, if there were errors or something else that the user should know. In case of a simple "connect to the configured provider" command the program needs not print anything if things went ok; you simply get a new command prompt. After this you should be able to surf the web, or at least ping some sites (provided that you got all the needed information trough dhcp or something similar, or configured DNS servers manually).
So, if you use pppconf, use pon/poff. If you use wvdial, see
and if wvdial.conf has it's own manpage, that too. Then edit wvdial.conf, which basically means "add in dial number, username and password and save", then try running wvdial.
There are graphical ppp programs too, if you prefer them; such as kppp (for KDE; there are similar programs for Gnome desktop too).