The post office experience can be a bit confusing for newcomers, particularly tourists here for…read moreonly a short term and who do not speak Czech. The most important thing to understand is that, as at the local banks, you need to take a number from a small kiosk just as you enter the main building. Select the category of service that you need, take the printed number, and then go to the main hall and watch the displays. For many of the services, tasks of a particular nature will be addressed at the same counter, so the ticket numbers close to yours will likely be for a similar service and at the same counter that you are waiting for.
Remember that postage stamps are called známky (singular známka).
While you are waiting, you can take in the lovely Art Nouveau design of the main hall.