I agree with the others, there are better alternatives to Zürich. You could also consider going directly from Zürich airport to Lucerne and spending a few days there while you get over get jet lag. It's a beautiful city and while there you can take a cruise on the lake, visit the fantastic Museum of Transport, see the famous Lion of Lucerne (which was mentioned by Mark Twain) or visit Mt. Pilatus or Rigi.
I'd suggest having a look at the Man In Seat 61 website, as there's a lot of information there that will help you to decide whether a rail pass is the best option for your circumstances. You can check rail schedules for all of Europe using the Bahn.de website.
If you haven't travelled by rail in Europe, you may find this helpful - https://www.youtube.com/watch?v=3AxtbifeoBY .