The Anmeldung, in English "registration", is one of the most important administrative prerequisites for anybody moving anywhere in Germany.
Important to know is...
You must register every time you move, even if you are only moving two blocks away.
You need to get an appointment either online or by phone (usually faster) at a place called Bürgeramt.
After completing your registration you get a Meldebescheinigung, literally “Registration certificate”, which you will need to open a bank account, sign a working contract, or obtain a tax number.
If you are moving out of Germany, don't forget your Abmeldung, "deregistration", otherwise the government will assume you are still living in Germany.