There are general courses but also special courses for young people or parents. There is generally a charge for attending a language or integration course. If you do not have a fixed income, you can apply to the Job Centre to attend a course free of charge.
However, some adult education centres also offer general German courses.
You can also use these to learn online but remember that all these offers cannot replace a language course.
You are obliged to attend an integration course if you
Further information and application forms can be found at the Federal Office for Migration and Refugees (BAMF).