No. The European Travel Information and Authorization System (ETIAS) is a visa waiver program, set to be implemented by the European Union by the end of 2025. It will not be in effect for our wedding.
You'll be fine with a credit card; however, it is highly recommended to carry spare euros with you in case you encounter a cash-only establishment. Many U.S. banks offer online currency exchange services and will mail the exchanged currency to you. Additionally, airports and some train stations have exchange booths. Switzerland does not use the euro but rather the Swiss Franc. However, most Swiss establishments will accept euros.
Travel restrictions implemented to control the spread of COVID-19 are lifted in the EU and Switzerland.
We highly recommend notifying your cell phone provider of your travels and purchasing an extra plan (if necessary) for your phone to work in France. Having the ability to make calls, send texts, look up directions, and pull up Google Translate (wink!) will be very beneficial!