These days everybody needs internet. In Prague there is lot of places where you can catch free wifi. Usually public buildings such as libraries have it or shopping malls. In new model of trams (the big ones with yellow stripe at the bottom) there is. If you are student you will receive the account on Eduroam and it works at all public university properties and even in larger amount of public buildings and not only in Czech Republic but it will give you a worldwide access to the internet in specific buildings.