Architecture student searching for a 1 room flat from September for long term

I am calm and introverted, and I respect other people's privacy. I am clean and can not concentrate if my surroundings are not tidy. I've been living in Germany from October 2023, and I just got my German degree. I want to start my studies from 1st October in Braunschweig, but i would like to move in sooner cause i need to get settled . I have my brother and some of my relatives in Germany, and they can support me financially in case of emergency because they all have incomes. My brother is my official financial support and can show you the documents needed in case of further questions.