The day we went it was ticket entry only (normally free entry). So, while waiting outside, we quickly booked a "tour" (Viator) which included entry and audio tour and was very reasonably priced. So we were able to just walk in and enjoy the audio tour as well, which was excellent and very informative.

Parce que c’est aussi une église…

Only on weekends do you need reservations. I wouldn't use an audio guide. If you do they are picked up right inside the doors. We went on a Tuesday and the line was long ti get in but still only a 5min wait to get in.

Achtung: neuerdings kostet das Pantheon Eintritt! 5 Euro!

Entry is free. You pay for an audio guide if you want one.

We visited Pantheon on Sunday morning just before mass. I’m not sure if you need to book or reserve to attend mass. I can recommend a private guide, it was worth every penny. Serena Cantagalli tours. She was an angel and showed us around Pantheon , St Angelo and Trastavere. Enjoy your trip.

Show your CDC card or your digital version of it. We were vaccinated at Walmart and we got digital versions of the CDC cards. The only problem with the digital version is that it has a QR code that is not compatible with the devices in EU, so when they scan it, it does not show validity. The way we overcame this is by asking them to read the digital version. This worked. We went everywhere with our digital version.

The Pantheon re-opened on Feb 1, 2021. It is currently open to visitors Monday - Friday from 9:00 to 19:00. It is closed weekends. You really should visit the travel forums section of this website - specifically the Italy and Rome travel forums. There is a lot of good information there about the current state of COVID-19 in Italy and what is opened / closed at the present time since it can change based on the COVID-19 numbers.

There isn't a metro st by the Pantheon but Rome centre is easy to walk to the locations

No e’ libero