Going to Italy in June 2022 for my honeymoon from the US. Questions regarding travel and trains

We are both vaccinated and have CDC cards. I searched through this subreddit to see the green card requirement does not apply to US citizens. Is this true? Do we only need to show them our CDC vaccine cards to be allowed entry into places/trains?

We are flying with ITA (new alitalia). will we run into issues in Italy regarding COVID protocols?

we will be using the train to make the following trips:

• Rome to Naples

• Naples to Florence

• Florence to Venice

• Venice to Florence

• Florence to Milan

Which trains do I need to take for the fastest route. Money is not an issue.

Any other tips? I've been to italy before in 2017, but I'm sure COVID has messed up a ton of things.