In Germany, unfortunately, you can not say in general how long you have to be in isolation or quarantine. The decision depends on the local health department. A distinction is made as to whether you have to be in isolation (affected yourself) or in quarantine (contact person). From the quarantine you can usually test yourself freely from the isolation not before the expiry of the ordered time.
And now it should also be differentiated with which variant one is infected, Omikron or Delta. Therefore, one can only rely on the statements of the health office of the district and according to the information of the German television, they have ordered 14 days of isolation.