Labor law in Germany is very unique compared to other law systems
First of all there are strict rules in taking legal actions or claiming wages etc. In cases of termination, there is a time limitation of three weeks. So if you receive a termination, you have to go to court within three weeks, even if you are terminated for a longer time. E.g.: You receive a termination on 1st of September and your contract of employment will be terminated on 31st of December. In this case, you need to sue at least on 21st of September.
If you claim missing wages, there are working agreements who force you to claim within two months.
Mostly it is necessary to sue in a case of extraordinary dismissal. There is a high chance, to change extraordinary dismissals to a contractual notice of dismissal. In case of extraordinary dismissals, you will receive unemployment compensation by job center (because of your mandatory unemployment insurance) twelve weeks after termination. So going to court means in nearly all cases to receive unemployment compensation the day after having received the dismissal.