The possibility to receive BAföG which means financial support (half donation, half credit) for first time studying, ends with your 30th birthday. If you already should have a Bachelor and apply for a Master, the end date for possible financial support is your 35th birthday.
So it is absolutely essential for you, to start studying Informatic at a German University before you get 30 years old. Is this still possible for you?
If you have a Aufenthaltsgenehmigung you have the right to study and it entitles you to apply for BAföG at the BAföG department of the university where you start studying. But this is only possible after you successfully have been accepted for studying Informatic by the university.
The Freie University Berlin has several consultation dates in the coming up weeks, in Arabic on the 1. of August and in English and German on the 15th of august, at the study service center, Iltisstr. 4., room K009.
A good site for further info on refugees and studying is:
Feel free to ask, if you should need further info.