Need apartment for rent in Berlin

I am an 18 years old male, coming to Berlin for a language course. I am looking for a nice place to accommodate me during my stay here. Im interested in having an entire apartment instead of having to share the flat with someone, but I also dont mind renting a studio. I want a good location in the city to make it easier for me to reach my school and enjoy the city at the same time. I would rather rent a furnished apartment or at least something that has the essentials (Bathroom, Kitchen, washing machine).