I have some helpful tidbits of information for those struggling to find items.
Night 2 items/Objectives:
The Cupcake can spawn in: 1, The Kitchen, far back on the left side, on a counter. 2, The Office on top of some boxes, near the desk and fan (You can see this one from the camera if you look carefully) Lastly 3, in the Springroom in the back row of chairs (You can also see this from the camera, I believe its 4 ish chairs down, starting from the left)
The Dreaded Pizza Slice can spawn in: 1, The bathroom, farthest sink from the door. And the only other place I know of it, is what I believe to be near spawn, under one of the pooltables. [My reasoning is I came from the Springroom, crouched behind one of them, because bonnie was coming, and than headed to Foxys cove to flick a switch, eventually at some point grabbing it on that path. Not very helpful, I know.] If it also has a 3rd spawn, I have no idea where it is, sorry.
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Night 3 Items/Objectives:
The Red Party Head spawns in: 1, Foxy cove closest room, on a bench in the middle, left of the door. Lastly 2, in the stage room, immediately turn right into the tables, in the far back on the last table, in the left corner. I never found/Encountered a 3rd spot.
The Toy Blaster spawns only in one spot from what I can tell, after 5 nights of testing (Heh): In the arcade, in the left isle, right next to the cola machine, lying on the floor.
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Night 3 is much easier for me, because of the whole pizza slice item, it took over 7 runs of it, for me to complete it, and Night 3 only took 2, crazy.
A simple strategy for Night 3, which worked every time for the most part, is starting by going to the phone, for the grace period, instantly going to foxy cove, and checking the closet, while earning the enter foxy cove objective, than if its not there, going to the table in the Stage room, than, which is a high likely hood, Bonnie going through the hallway towards office, you can simply go into the Vent in the stage room, that leads to the Arcade, to finish up, and obtain the Blaster.
While doing this, you can press t while moving, than pressing 2, to have passive foxy boredness drop to 0, while you roam around finding the items, after all is said and done, you can hide in the office, till time runs out, while hopefully, not having to deal with bad gen spawns. Once bonnie also goes to patrol the mangle room, you can get Battery life, if you so desire it. Pretty simple Night compared to 2.
Lot of text in this post, hope it helps. Wish strafing was a thing in this game. 4 Stars, could be 5.