Being one of the largest metropolitans in Europe, Berlin may be a little overwhelming to begin with.
We have put together some tips for you to help you explore it maximize your experience!

Getting around 

Berlin is flat! making it ideal for walking and for riding bikes. For the price of no more than €12 a day you could cover long distances and take a ride through the city’s parks and experience one of Berliners favorite past time activities. 

Having that said, watch out for cyclists! 
There are a lot of bicycles in Berlin and on the walkways, the road is divided into 2 sections. One side for pedestrians and one for cyclists. If it’s your first time visiting Berlin, it’s easy to wander onto the wrong path. Most cyclists will ring their bell if they’re coming up behind you, but it’s best to stay aware and off the bike lane.

Berlin is home to one of the worlds busiest and vastest Public transportation networks, enabling you to go anywhere you want, all in one ticket for all means of transport.
The system works under the rule of trust, meaning it is generally open for everyone to use even without having a ticket. Sounds a little crazy but getting caught will reward you with a  €60 fine per person. 
AB zones comprise of the city center, C covers the outskirts so it is relevant only when going to Potsdam, Memorial Museum of Sachsenhausen Concentration Camp and Schönefeld airport.