You can check where you are allowed to consume in public on this website (click the button saying “Verstanden, zeig mir die Karte!”, you are agreeing to a no warranty disclaimer): https://bubatzkarte.de
The regulations don’t apply to private spaces and only when in sight of the protected locality in the centre of the red circles.
And there are other regulations, so many other regulations…
But hey, I can at least legally consume in the privacy of my own home now, so I got that going for me, which is nice.
You should read this map mindfully: Outside of the Red it is fine to consume. Inside the red areas you may consume it if you are outside of the sightline of kindergartens, schools, and playgrounds etc.