I love Gloom! We have it :D. I reckon a library would be a great space to run a D&D (or similar RPG) game too. TBH, as a teenager I didn’t go to the library much. My local library was small and dingy and the lighting was awful. So I just borrowed books and returned them and that’s all I did there. I think a lot of modern libraries are much nicer spaces, but they still have the “this is an adult’s space” feel to them (except the kids’ section, but teens don’t want to hang out there and I don’t blame them).