If you share your WiFi with the Vodafone community, your credentials are your main Vodafone account username & password.
Should you have forgotten your password, you can reset it for Vodafone Italy users clicking here.
Connecting abroad (outside Italy)
To connect outside Italy, add the prefix VF_IT/ before your username to create your roaming username, e.g. VF_IT/name@gmail.com. Start a session with your roaming username and your normal password.
More details about how to connect: