again, it depends from Land to Land.
Germany is a federal state and laws are different.

In many states (e.g. Hessen) you are required by law to wear a FFP2 mask.

However,
this is never enforced.
I never seen or heard - and I've asked around - about anyone being warned of fined in such regard.

You also need to wear a mask when entering into any indoor space (restaurant, pub, mall, public building, office).
The only exceptions nowadays are for example gyms, where you are exempt to wear a mask because only vaccinated members are allowed.