Hello John and welcome to our community!
In Germany the so-called Standesamt (register office) is competent for marriages. You can go there and ask them which documents you need to provide in order to get married.
We had a question that is quite similar to yours here on the platform recently. Please check out the information provided there by following this link:
https://***.wefugees.de/k/questions/2207
Best regards,
Thorgen