One day trip I really enjoyed was the round trip from Lucerne to Mount Pilatus. I used the boat from Lucerne to Alpnachstad, the Funicular to the top, the cable cars on the other side to Kriens and then the bus back to Lucerne. You can also do the trip in the reverse direction. There are restaurants at the top where you can have lunch with wonderful views before making the return trip. It was a wonderful day! You can buy the tickets at the T.I. in the Lucerne station.

Another popular trip is the trip to Rigi, but I haven't taken that one so don't know the route. This is another possibility, although not a regular tourist activity - https://unterirdisch-ueberleben.ch/ .

You'll get some good ideas on other day trips and where you can eat and stay by having a look at the RS Switzerland guidebook - https://store.ricksteves.com/shop/p/switzerland-guidebook .