I don't know much, but I'd try 10 different things as rapidly as possible and see what sticks. You're in Berlin. Why not have some tutoring business specifical

I don't know much, but I'd try 10 different things as rapidly as possible and see what sticks. You're in Berlin. Why not have some tutoring business specifically to Berliners? Then after you've done some tutoring, anticipate whatever next-level skill they need and upsell those online courses. Just brainstorming