Arno has certainly pointed yo in the right direction.
Luzern ( I use the German spelling, since it is in the German-speaking region, and that is what you will see on the signs in that area) is a good place to start.
It has a diverse mix of activities and types of scenery and sights, all nearby.
Another advantage - Luzern is close enough to the airport in Zürich that it is a convenient place to stay immediately after your arrival, or even on the night before you fly home, depending on your flight time.
From the airport to Luzern, there are two trains per hour that go the shortest route - through Zürich main station. One goes all the way to Luzern, the other requires a change of trains in Zürich.
The timetable -
and a map -
can help you think about where you might want to go and how long it will take to get there.
Please read about using the timetable in the link that I provided above.
We can better advise you if you give us an idea of your interests. For example, some people go to Switzerland for the specific purpose of riding as many of the various trains as they possibly can. Other like to hike...in the mountains or in the countryside. World class art museums?
Unless riding all the trains that you can is your objective, I'd suggest that you might want to use no more than two bases during your stay, to avoid spending a lot of time getting in and out of hotels.
I have attached a few of my favorite pictures from my trips to Switzerland over the years, and a screen grab from the timetable to show those trains, in July. In the timetable, clicking on the "+" beside each journey will expand the details.
(Ooops - the screen grab I posted shows the trains from Zürich main station.
I'll add another one from the airport).