Loot is randomized in most of the places it can spawn nothing most of the times
Ok lets start easy, boxes in the corner of spawn are hiding iron bars that can be broken.
Items: Pills or Bandage.
Going down stairs you can break the wall in front of you.
Items: Medkit; Hatchet .
After reaching the top of the ladder you can break the wall on the right.
Items: TNT or Grenade; Any Pistol; Walkietalkie.
After leaving the tunnel you will find a door on the left that can be opened with a key located in the second alley way on the left.
Items: Shotgun, Pistol or Rifle; Melee Weapon.
Garage door on the right can be opened by placing next to it a big propane tank (located behind the fence in the corner) and shooting it.
Items: CZ, Colt, Mac-10 or MP5; 7.62 or 45 acp ammo.
Close to a propane tank behind a cooling tank you can find a box that can be broken.
Items: 357, 45 acp or 7.62 ammo
Inside a shed corridor you can interact with the bottom of the wall on the right.
Items: Bandages or Pills; Gene therapy; TNT, Molotov or Grenade.
After meeting with dad, inside the building on the right, you can put out the the fire revealing ladder leading to the attic.
Items:Rifle; 5.56 or 7,62 ammo; Gene therapy(maybe 2 at a time); TNT, Molotov or Grenade; random melee weapon, Walkietalkie.
At the end you can find a metal shutter in one of the alleyways, you can open it with a welder
Items: Shotgun or Rifle; 12gauge, 9mm, 308 or 357 ammo; Fire Axe or Machete.

Metal bar door inside a room full of kennels can be opened with with pliers located on top the table inside the first shed.
Items: Chainsaw, Rifle or Shotgun; Gene Therapy(2 pieces max)
This door inside facility can be broken
Items: Rifle; Fuel; Pills or Bandage;
After fixing electric trap and jumping to the next roof you can open door on left with a welder.
Items: Abrasive Saw, Shotgun, Pistol; 357, 45 acp, 9mm, fuel or 12gauge ammo; Gene Therapy, bandage; random melee weapon.