Dear
@Miky,
Thank you for reaching out to the community again!
I can see that you have asked similar questions about applying for asylum for the second time before. The answer Thorgen provided on this thread still applies to some parts of your question: https://***.wefugees.de/800325/applying-asylum-germany-again-after-voluntary-return-syria
That means: if you have left the country for at least three months, the second application for asylum you make in Germany might be treated as a new case.
As for your second question - whether you can withdraw the rejected application and continue to study in Germany - I will link our asylum law expert
@Nilab here. She will get back to you shortly!
In the meantime, you can have a **** at this website. There is a section about rejected asylum applications and your options to appeal the decision: ****://***.asylumineurope.org/reports/country/germany/asylum-procedure/procedures/regular-procedure
All the best,
Isa