Dear @Musawvir,
thank you for your question and your contribution in the community.
As for your question:
1. If the marriage done abroad is effective and recognized in Germany, you can apply for a residence permit for family reunion as a husband of a German citizen at the immigration office. Information on the required documents can be found under the following link of the immigration office Berlin
****://***.berlin.de/labo/willkommen-in-berlin/dienstleistungen/service.245714.php/dienstleistung/305289/en/
I hope I could help you with the information above, if you need further guidance please use the platform and we will be glad to help.
Best regards,
Nilab