Get all players?

How would I make the script go through all the players, and effect all of them? (Global script in the Workspace) Here's two things I tried:

for I,v in pairs(game.Players:GetPlayers()) do
local randomCoor = coordinates[math.random(#coordinates)]
local knife = game.ServerStorage.Knife:Clone()
knife.Parent = v:WaitForChild("Backpack")
game.Workspace.lobby.timer.SurfaceGui.timelft.Text = "Round In Progress..."
c = v.Character or v.CharacterAdded:wait()
c.Torso.CFrame = CFrame.new(randomCoor)
wait(60)
for I,v in pairs(game.Players:GetPlayers()) do
c = v.CharacterAdded:wait()
v.Character.Humanoid.Health = 0
end
end

Those didn't effect all players though, it only effected 1 player at random, for both. This is just a cutout of my script, but please help with

You need to create a clone of the knife and give the clone to each player, otherwise the knife will not be in ServerStorage for the next iteration over the players:

game.ServerStorage.Knife:Clone().Parent = v:WaitForChild("Backpack")

You are also waiting for 60 seconds for each player before then killing each player. It is unusual that you are iterating over the players inside a loop that is iterating over all the players. I can't tell what your intentions are there. If you tell me what you want it to do, I might be able to help further.