I travel to Europe twice a year, on average.
The critical piece of info is to own your phone, so you’re not tied to an agreement with ATT or Verizon. They most probably won’t let you add a European SIM if you are financing/monthly plan.
I have a Vodafone E-SIM. The plan is Callya, a prepaid plan. In January, I paid 20€ for 20gigs of data for 30 days. There’s a bonus, as of today, for 30 gigs for 20€
It’s valid all over Europe, so changing countries is not as difficult as it was 10 years ago.
I disconnect my local US line and activate my Euro SIM when I land. I get no US messages, but I get email.
if you keep your US number active, watch out for your message app scanning for messages, you pay for US data during those scans.
I use WhatsApp to call friends, so I don’t pay international rates at home or abroad.
I use my phone for photos, maps, CarPlay, buying public transportation tickets, tour tickets, boarding passes etc.
My credit card notifies me of all charges through my phone/Apple Watch.
I would be lost without my phone.
if you keep your phone, I recommend that you turn off all Cellular data before you land. Using WiFi is fine. Go to a local cell phone provider and they will help you connect to an ESIM or SIM card.
It’s the cheapest way.
In theory, you could buy a burner phone and a SIM card there. Depending on the service provider you choose, it is possible that you need a local address to activate.
Clear as mud? Ask me questions.