Friedrichshain is an up-and-coming neighborhood in the former East Berlin. There were a slew of restaurants and bars right outside the door. The large S-Bahn station, Ostkreuz, was only 8-12 mins. away by foot. We had trouble using Google Maps to navigate from Ostkreuz to the apartment since the GPS signal was not strong and, at the time, Ostkreuz was under heavy construction. To get to the apartment, walk toward the McDonalds in the S-Bahn station and then go down the stairs to the street. That will bring you to Neue Bahnhofstraße and, from there, it's easy to navigate to the apartment. Although there were multiple coffee machines, none had the requisite coffee capsules, so our first night was spend shopping for these for the next day's breakfast. Unlike most AirBnBs, there was little in the way of tourist brochures, etc. with which to plan your time in Berlin. By opening the door to the balcony and the windows in our bedroom, we got a cross-vent which made out stay much more pleasant.
But everything one would need was within a very short walking distance: a bank (Sparkasse) right across the street and a supermarket (Lidl) with five minutes walk.