How to make non school friends in germany

Im going through a friendgroup crisis rn since a friend is randomly leaving the group and only three others are left and its like, the group just doesnt function now and I mean, I could just talk to the others but I also dont wanna leave the remaining members of the group..THATS WHY I wanna meet some new friends outside of school.

Im talking about meeting other cool alt minors in germany.Like Ive seen some here and there but BROO where can you actually meet them??I know of a cool guy who visits lostplaces but the only thing we do is react to each others insta stories once in a blue moon and I dont wanna just ask him "oh yeah so..I havent met you in years but can wr meet up?"

Soo my question is: Are there like specific hobbies you could join to find alt people?Or are there any other ways?Specifically in NRW.Dont wanna give out more of my info so yeahh idk :)