Thank you for sharing your question with us and Welcome to the Wefugees community!
First of all, please note that I'm not a lawyer, so all the information I link here stems from my own research and from our platform.
In your case, appealing the decision is one of the first steps you can take after a rejection.
There is a very helpful site by Flüchtlingsrat Niedersachsen on "9 Perspectives after a negative decision on your asylum procedure": https://www.nds-fluerat.org/leitfaden/8-perspektiven-nach-negativem-abschluss-eines-asylverfahrens/
It's in German, but the translation (with a translating program) is quite accurate :-)
Also, there have been several questions and answers on our platform that discuss a very similar topic. You can have a look here:
How long does it take until BAMF sends their decision after the court hearing?
How long does it take to get a response by Ausländerbehörde?
I got rejected and appealed in court - What are my chances to stay in Germany?
Unfortunately, it's impossible to say how long it will take or what chances you have, as German bureaucracy is not the fastest and it highly depends on all the details of your case. If you have consulted a lawyer, he will be able to assess your case, but even then it depends on the court.
I hope these links help a bit. Feel free to reach out to us again if you need any further assistance :-)