We land in Zurich first thing in the morning after an overnight flight from the US. We have a one night stay until a flight the next day to Bulgaria. We are booked into an hotel near the airport just for convenience but thought we might go into Zurich for the day and do a bit of sight-seeing. Any recommendations on what to see? Also, how many Swizz francs should we get for incidentals? Will most restaurants in Zurich accept our US chipped credit card?
Zurich is more of a business and residential town--and it's not in the Alps. You might look at Wikipedia to see if there are any travel sites that interest you.
When traveling internationally, I use credit cards whenever possible because there are some some legal protections that ATM cards don't provide. We use our ATM to pickup spending cash, and even then not that much. Hard to know how much cash you'd need in Zurich for one day.
Zurich is a bit too sterile for my taste. In your shoes I would head to beutiful Luzern instead. It's only an hour away with direct trains available at the airport train station. Here's a taste of Luzern: https://youtu.be/NYy_maSNnco
Some one recommended to see this earlier.
https://community.ricksteves.com/travel-forum/switzerland/zurich-s-fraumunster
what to see? you might get some ideas from Rick Steves video
https://www.ricksteves.com/watch-read-listen/video/tv-show/great-swiss-cities
The Swiss National Museum across the street from the Hauptbahnhof is nice if Swiss history is of any interest. A boat ride on the Zuerichersee is fun in nice weather.
100 CHF might get you through the day, supplemented by your credit card.
Rick's recommended walk is pretty simple, down one side of town along the river to the lake, then back up the other side. It's pretty and not taxing, there are churches and stores along the way and places to eat and drink.
Credit cards work everywhere a tourist is likely to go, but it's always good to have walking-around money. I like about $100 worth of the local sheckels, you could try $50 for a day. The train from the airport to town isn't long, but make sure you include enough time to pass through airport security again.