In Italy, many public WiFi sources require that you log in. You can log in with a Facebook password or Google password.
YOU MUST REMEMBER YOUR FB PASSWORD.
Of course, your FB password is stored in your Google account. But this is only available if you are online.
So, if you don't remember your FB password, you cannot find it in your Google password list unless you are online.
This is called "Catch 22".
This has caused no end of frustration, since I did not remember my FB password.
So get this password saved in some other location.
I have a portable hot-spot device that I am using at this exact minute to be online.
We almost missed our train, as the tickets were on trenitalia and not printed. I could not get online. Fortunately, after going to the ticket office, agent was able to find the ticket. You cannot display your trenitalia reservation unless you are online. See discussion above.