Where are you gonna visit exactly?
There're basically 4 types of places where you can have sex with prostitutes in Germany. 1. Laufhaus is a building where every hookers sits in front of her room waiting for her client. No appointment is required. You just go there fuck whoever is free, assuming you are low inhib enough. Prices here are the cheapest (like 30€/20min).
2. Terminwohnung (appointment flat) which looks no different from a normal apartment but is specifically designed for prostitution. You need to find the local hoes online, call them, make an appointment to visit them. Prices vary from 50€ to 100€/30min.
3. Sex clubs aka brothels. You can call in advance to book a certain hooker you wish to fuck, or you just show up and pick whoever is not occupied on spot. Prices are similar to those at Terminwohnung.
4. Escorts. To find call girls you just need to Google "call-girl + your city" and visit the homepages of professional agencies. Normally these escorts only work part-time and have a normal life so you probably can't see their face in advance. They're also the most expensive option : 150€/1 hour at least.