Ground transportation
The HU Berlin nicely described how to reach the Charité Campus Mitte by train, bike or car. How to get to there?
Most easily the Charité CrossOver can be reached by foot from Berlin Central Station (10min) or Berlin Friedrichstraße (20min).
Airports
Both, Berlin Tegel and Berlin Schönefeld Airport have terminated their services but the newly opened Berlin Brandenburg Airport is well-connected to the City Center.