American Experience Getting into Czech Republic Here? Documents?

for covid if you have been continuously in Italy for 14 days your Americanness is irrelevent. Where you have been in Italy is. For immigration it would be your Americanness.

Do you have an EU Green Passport?

I have been in Rome and Sicily (Catania) since I've been here. Took a train from Rome to Catania. That is all. How can I get a Green Pass if I am not an EU citizen?

I had US tour clients from Italy this week who were previously vaccinated in the US. They had to fill in the Passenger Locator form at https://plf.uzis.cz/ and because their vaccination certificates were not considered as "National" they needed antigen tests 48 hours before arrival. Basically so long as you are in a green list country for 14 days before arrival here and you have at least a negative antigen test result then you can enter.
This thing with the "National" certificate is what is causing issues. Quite simply a "State" system is not being recognised so currently US visitors to EU countries are basically being treated like they are coming from Amber list countries hence the need for the antigen test.

KLM has said something about needing a PCR test before boarding my flight from Catania->AMS->Prague. What will actually happen at the airport in Catania? This PCR requirement seems to be at odds with everything else I am seeing. It's been impossible to get an actual human being on the phone at any point.

The current advice for arrival from Italy to Amsterdam by plane is at https://www.government.nl/topics/coronavirus-covid-19/visiting-the-netherlands-from-abroad/checklist-transit-or-short-stay. You are arriving FROM a schengen area safe country and you are travelling TO a schengen area safe country and spending less than 12 hours in Holland so as far as the government is concerned you need no testing at all and only complete the health declaration form which may be part of the KLM booking process.
As far as Czech is concerned the Netherlands is an amber list country so what I said earlier still applies. But individual carriers can stipulate their own requirements for travel like KLM . So to be sure of travel when you arrive at Catania you will need a negative PCR 72 hours before departure, fill in the passenger locator form for CZ and health declaration for the transit in Amsterdam.

I plan on flying to Prague day after tomorrow from AMS. The CZ website is crazy complicated to understand. The US Embassy website says tourism is allowed. KLM's app says it is not. But the US site was updated Nov 9, whereas the CZ site was updated Oct 27. I am Moderna vaccinated, and I can easily get a PCR test. Will I actually get into the country? I will have been in AMS exactly 14 days when I arrive in Prague. Any recommendations on who I can contact or if I should just try it? My flight doesn't get in until 11:00-11:30PM in Prague. Thanks!

elise you should probably post your own question - better chance of it being seen rather than on the last page of a 4 month old question

If you have a negative PCR test from 72 hours prior to your entry, I sincerely doubt you will have a problem. When I went through in July, the Czech border people didn’t even so much as look at my passport, much less my vaccination information. I think that this was merely a fluke, but it also says something, too. I tried to take out my passport and they literally waved me through even more vigorously.

It’s mostly just very stressful (and sometimes costly) to traverse international borders in this moment. But if you’re on top of your game (read: paperwork) it’s no biggie. Also, on a less helpful, more hopeful note remember that pandemics do end.