Current Covid restrictions?

Gutentag freunde!

I'm planning on visiting Köln for the weekend from Belgium. But i'm having a hard time finding the current Covid restrictions online.

Do you currently need a negative test to enter museums of restaurants? Are there any restrictions in hotels or hostels? Is it mandatory to wear a mask in the streets?

My second vaccination was only monday so i'm not clear yet. I do have a negative test to cross the border if needed but it won't last me all weekend if i need it for anything in the city (usually they want the test to only be 48/72hs old)

Thanks!