No, you do not need to speak German to study in Berlin. The city is very international, which means in your day-to-day life you’ll be able to use English to get pretty much everything done, especially since you’re still a student. Berlin has universities that offer courses in English, not being mandatory that you speak German to attend your classes and exams. You can of course learn some basic German it can be great for small interactions at services, restaurants, bars, or simply groceries shopping.