German residence permit

My name is prince. I am from Nigeria living in kosovo   . Here to get germany embassy visa booking takes over eight months because of the crowd and high population of people applying for visa . So I was able to get a visit visa booking . I am now married to a german citizen . I want to ask, if I get to Germany with my visit visa , can I apply for residence permit  , because I am already married to a german wife .because it will take several months to get family reunion booking at the german embassy in kosovo , and another months to submit application. I have waited several months to even get a visit visa application. Can I apply for residence with my marriage documents when I get to Germany with my visit visa ?.

I don't think it is possible to apply for a family reunion visa inside Germany, but your wife should ask about it at her Auslaenderbehoerde.
Also: Basic German language skills are required to get the family reunion visa. Do you have them?

I am still learning german language.   To get family reunion visa need a long duration booking.  Im married to a german lady and I have visit visa. Can I get a residence with it.

As I wrote above (did you read my reply?), to my knowledge it is not possible to apply for a family reunion visa (or convert a visit visa to it) within Germany. You can only get a residence permit if you hold a residence visa (e.g. a family reunion visa in your case).