If you want to go on a trip further, no problem… We have quite good transportation system arround the country.
There’s a public transport journey planner on the address www.idos.cz. It can find journeys using trains, buses and city transit. Some buses and trains have compulsory reservations. Threre are some lines, where reservation is recommended during rush hours (especially on friday afternoon).
Or you can download an app called PubTran, which works as journey planner for buses and trains around the whole Czech Republic as well as journey planner of the public transport in Prague 😉 It even includes the night buses and trams.
The railway tariff is quite complex, but if you know how to use it, you can travel for cheap. The railway company provides a tariff suggestion generator. Usually you buy the tickets at the station and they usually accept payment cards. For some directions (esp. for international travel) it is better to buy in advance online.
If you want to travel abroad by train, it’s pretty difficult to find the right tariff. There are some discounts on the railway company website, but sometimes there are better options. Other option may by to go by bus. International lines can be mostly found on the IDOS or at the webpage of one of the bus operators (StudentAgency, Eurolines, OrangeWays, MeinFernbus). You’ll have to buy ticket in advance for the international lines.