The postdoctoral phase centers around independent research. You will broaden your research profile, develop new ideas for research, and acquire third-party funding for new research projects. Observing the rules of good scientific practice should be a matter of course.
To support your research activities, you can apply for a temporary position for principal investigators or a junior research group that you will lead independently. Well-known funding programs include, among others, Emmy Noether Programme by the German Research Foundation (DFG), the Starting Grants of the European Research Council, or the Helmholtz Young Investigator Groups.
An overview of individual funding options is provided on the HRA website. The Goethe Universität Frankfurt has summarized funding options for postdoctoral researchers in their Förderkompass (PDF in German).