Depending on your country of origin, processing this visa could be as short as 3 months or as long as two years. In certain African countries, it's almost impossible to get this visa.
For Ghanaians (should be applicable to other Africans), you would need to provide the required documents listed above or see image below (in German). All documents provided must be translated to German by a certified translator
Here is a personal experience from Munich. It would most likely be the same in other cities in Germany.
No fret if your institution is not listed here. You can always write to the university you are applying to when in doubt. 🙂
To study in Germany, you need to be accepted into a university. Your financial status is not an admission requirement. You can apply to any university of your choice.