I see that you ask very many questions. What you need, it a good councelling center (Beratungsstelle). Perhaps there is some consulting for refugees / asylum seekers at your university. Some of them provide it nowadays. And there are a few so called "refugee law cliniks" in different German universities, where students of law try to help refugees with legal problems.
Where you will live during your asylum procedure, depends on your country of origin, because not all countries of the world are proceded in each federal state You will be sent to one of federal states which proceeds your country, corresponding to a special quote. To change it can be difficult and in the earlier stage probably impossible.
Studying is not an "occupation" in terms of law and therefore is not directly prohibited by the law during the first stage of the procedure. But in the camp where I work the authorities make a ban on studing (it stands on the camp documents of inhabitants) which means people must fight against it if they want to start studing.
It is possible for the authorities, after the last changing in the German law, to keep you in the camp for 18 months and even longer in some cases. And the federal states even have a right to keep people in the camps for 2 years, it is their discretion.
If you ask for asylum, you will have money for asylum seekers. There is no special money for you as a student if you don't get a positive decision and a residence permit.
It is difficult to tell you more. Each case is really individual.