Where does the CFrame go after CharacterAdded?

game.Players.PlayerAdded:Connect(function(Player)

    Player.CharacterAdded:Connect(function(Character)

        local clone = script.Parent.Jetpack1:Clone().
cone.Parent =  Character

    end)

end)

You want to set the cframe before putting the object into workspace, it saves memory.

game.Players.PlayerAdded:Connect(function(Player)
    Player.CharacterAdded:Connect(function(Character)
         Torso = Character:WaitForChild("Torso”)
        JP = script.Parent.Jetpack1:Clone()
        JP.CFrame = Torso.CFrame
        JP.Parent = Character
    end)
end)

But there are still 2 problems with this script. 1. We are placing the jetpack at the same position as your torso, effectively putting it inside your character. 2. We are only setting the position once, so when you move the jetpack won't follow you. To fix this, we will offer offset the CFrame, and use a weld.

game.Players.PlayerAdded:Connect(function(Player)
    Player.CharacterAdded:Connect(function(Character)
         local weld = Instance.new(”Weld”)
         local Torso = Character:WaitForChild("Torso”)
         local JP = script.Parent.Jetpack1:Clone()
        JP.CFrame = Torso.CFrame
        weld.Parent = Torso
        weld.Part0 = Torso
        weld.Part1 = JP.Handle --you might need to change handle for another part in the jetpack
        weld.C0 = CFrame.new(0, 0, 1) -- this will place it .5 studs behind your back, which should make it look like it's sitting on your back
        JP.Parent = Character
    end)
end)