What documents should I take to the interview for my US B2 visa application?

The required presumption under U.S. law is that every visitor visa applicant is an intending immigrant until they demonstrate otherwise. Therefore, the documents you present must overcome this presumption by demonstrating:

• That the purpose of your trip is to enter the United States temporarily for business or pleasure;

• That you plan to remain for a specific, limited period;

• Evidence of funds to cover expenses in the United States;

• That you have a residence outside the United States as well as other binding ties that will ensure your departure from the United States at the end of the visit.

https://travel.state.gov/content/travel/en/us-visas/tourism-visit/visitor.html

This https://de.usembassy.gov/interview-and-supporting-documents/ will help you figure out the documents you need and how to approach the interview https://de.usembassy.gov/interview-and-supporting-documents/ (thanks to @Phoog for the link)

As to your chances of getting the visa, no-one can predict that.