This location is filled with feral ghouls. Some of them will even climb in from the windows. The room to the SW near the entrance has a novice terminal and advanced safe. The terminal can be used to activate the protectron or open the safe. Two nuka-cola quantums are found in the soda section.
The green steamer trunk and Josh's body is found in the northern corner room. (Consult your local map)
Minuteman corpse to the NW, inside the Employee's Only room. Inside the restroom, there's an ammo box, first aid kit, and scattered ammo on the floor. Outside that room, look for a magazine rack beside the Milton General Hospital billboard. You can find an issue of Tales of a Junktown Jerky Vendor there.
Room to the SE corner has an Expert wall safe and a chem station. There's a generator in the middle-eastern side of the building, with an active fusion core.