Nizar Shakhin
A few words about my experience in the double degree program. I needed a lot of documents for admission, but it didn't cause any major problems. There were no problems with housing either, I quickly found a place in a student town near the university. The two closest dormitories to the compass are Eselsbergsteige and Upper west side. Here you should choose WG-type housing, because there are the most of them and you are guaranteed to get a place there. As for studying, the first time was terribly difficult, especially the preparatory course, where at that time, I didn't know mathematical terminology in German yet, so it was difficult to relearn. But over time I got used to it and studying became easier and didn't require as much time and effort as it did at the beginning. I just had to get used to it and get used to it. The exams here are more difficult, but it's realistic to pass them, I prepared for the math exams for 1.5-2 weeks and got a score of 1.7 for two exams. It is very useful to independently review the material of the first semester before starting the lectures of the second semester (materials for students are in open access).
The problem I encountered was registration. It was all because I had a residence permit in one state other than Ulm in paragraph 24. And so I had to cancel this permit so that I could live throughout Germany. It takes two weeks to register, then a fine of 20 euros. But by the time everything was done for me and I was able to register, I had already closed the session, that is, about six months had passed. This issue should be addressed as soon as you receive a housing contract. But I did not pay the fine, because in fact I could not do it earlier, so I was not asked to pay it.
BAföG - I applied for it around April and was approved for it in a month or two. Although there are cases when you have to wait longer for confirmation.