From Bonn to Berlin for doctorate studies

I recently graduated from University of Bonn, holding a Master of Science degree in biology. I'll be relocating to Berlin from Bonn in May for my doctoral studies. I'll be working as a full-time PhD in a medical research institute. I'm a very joyful, tidy and quiet person that likes socializing with new people over a glass of wine. Probably because I grew up in different countries (Originally from Iran, lived in Switzerland, USA and now Germany).
Although I'm sad to leave my friends in Bonn, I look forward to making new friends and exploring Berlin.
Ideally, it would be great to have a long-term accommodation but I don't object to short-term rentals as well until I actually move to Berlin and find suitable long-term accommodations.
I don't smoke and I don't have any pets.
Thank you for your considerations.