1 day in Zurich, what should we see?

I agree that Lucerne is beautiful, but after arriving from the US I do understand wanting a pause before launching onto the whole vacation. Touring by bus does nothing for me. But, if you want to stop in Zurich I would recommend visiting the Fraunenkirche with its fabulous Marc Chagall windows, the Swiss National Museum which has excellent collections, particularly prehistoric ones, and taking a leisurely Lake Zurich cruise. Walk around, visit some sights to get into the time zone and launch the following day. Have fun.

Do a lake cruise. Beautiful. No need to book, just walk town the river to the lake and you'll see many choices.

One night stays do not bother me as much as others on the forum, but for the amount of time it takes to travel to your Zurich hotel and check in, you could be almost to Luzern for a multinight stay. I could see staying in arrival city if the next town is hours away, but Luzern is so close. Also, you will be shorter on time in Luzern which is an absolutely stunning city.

That said, if there is some sight in Zurich that you are particularly excited about, then by all means, its worth it to spend the night.

If I'm understanding correctly, you are arriving 3 days (or nights?) before a river cruise and think you would like to visit Zurich, Luzern and Basel?

Seems to me that you should peruse some travel guides and watch some youtube videos to get an idea of what you are most interested in.

A quick site in Zuerich is the Fraumuenster Church with its very attractive stained glass windows by the 20th century artist Marc Chagall.

If you have more energy and intellectual appetite, the Swiss National Museum will give you all the information you ever wanted about Swiss history and culture (in English).

Rick deals with this and so much more in his videos and his guidebooks, watch and read them