Teaching and supervisory tasks
Beside research, teaching is the main task of responsibility at German universities.
On your way to a professorship, you should start gaining teaching experience in the postdoc phase at the latest. It is part of your academic qualification. It's not the quantity that matters, but the variety. You should cover one or two courses of different formats (seminars, exercises or even lectures) per year, even if it requires more preparation work.
If you do not have a teaching obligation, you should try to find a teaching position (possibly unpaid) on your own initiative.
At the OVGU, the project "fokus:LEHRE" of the Faculty of Human Sciences offers workshops on preparing and conducting courses, on testing and on digital formats for teachers.
Teaching experience also includes supervising student theses. Here you should take on 2-3 student theses per year.