If you need help here's a guide to where to find all items (Spoilers):
Crowbar: On the antenna on the roof you get there by stacking boxes.
Magnet Gun: In the backyard. throw a basketball at it.
Key (small room): in the party room in the empty chair
Key (Neighbors room): in the small room Bookcase. gotten by using the magnet gun.
Keycard: In the neighbors room on his table
Gun: At the porch.
Key: (To Black Key Room) One of the keys in the bathroom behind the wall.
Key: (Basement Key): In the room near the entrance.