There was a series of books I read when growing up that I enjoyed. It was old then, and not exactly mainstream, so I'm not sure it's still available. I thought I would mention it anyway.
It was Alfred Hitchcock's Junior Detectives, or something like that. I think there was more than one author. It was three boys, one whose father owned a junkyard, one who was brilliant, and one who was athletic, I think. The junkyard had an old trailer home, tucked away in a far corner, that had been forgotten. The boys created a kind of maze, I think, to get to it. That was their clubhouse, and office when they formed a detective agency.
Given the Alfred Hitchcock brand, the cases were more suspense than crime. Ghosts, etc, frequently seemed to be the criminals, and the boys had to prove it was real people committing the crimes, plus identifying which people. There were some clues that were interesting.
I enjoyed that series after finishing the eight Agatha Christie mysteries our library had. There were more of these Alfred Hitchcock Junior Detective books.