If you have doubts regarding COVID-19 (regarding rules, vaccines, quarantine and so on) you can contact one of the numbers activated by the Italian Ministry of Health.
Operators answer every day 24 hours a day
From Italy: 1500
From abroad: +39 0232008345 – +39 0283905385
If you need info about how you can obtain the Green Pass you can contact 800 91 24 91 (every day from 8:00 am to 8:00 pm) or you can write to cittadini@dgc.gov.it
All info here
If you live in Tuscany you can also contact the regional COVID-19 public number 055 90 77 77 7
Info here