thank you for sharing your question with the Wefugees Community!
In general: If you ask for asylum in Germany you first receive a "Ankunftsnachweis" and will be sent to a specific district or city within Germany that is now responsible for examining your asylum application. There you will formally file your asylum application with the Federal Office for Migration and Refugees (BAMF). By this time you should now have gotten a resident permit for asylum seekers ("Aufenthaltsgestattung").
The interview should now be the next step. But I can´t tell you a concrete number of days or weeks how long you will wait for your interview. It depends where you are located exactly since there are for example special refugee facilities where the process is faster as the regular process.
But: If you don´t yet have your appointment for your interview you should use the time and go see a local counselling centre close to you. They offer a preparation for your interview for free ("Anhörungsvorbereitung") and tell you exactly what is important and what you can expect from the interview. Via this link you can find free and trustworthy counselling centres close to you:
There are also always the Refugee Law Clinics which offer free interview preparation. You can check here if there is one close to you: http://rlc-deutschland.de/mitgliedsorganisationen/
I hope this answer was helpful for you. If you have more questions or need help finding a counselling centre close to you, let me know or ask your question with the Wefugees Community!
All the best
Note: Please keep in mind that we can´t provide qualified legal advice via the internet and that any information given can´t replace such legal advice.