Your obligations as a citizen does basically involve respecting the rights of others. In addition you have to follow the rules set by the federal government, the federal states and the community you live in, including such things as informing the local authorities about all they need to know and paying your taxes properly. You can find a brochure with more information at:
https://www.buergerstiftung-aachen.de/wp-content/uploads/2016/05/BST-Grundrechte-DinA4-DE-RZ.pdf
This brochure is also available in Arabic, Farsi, English, French, Kurdish, Tigrinya and Turkish.