How can I make this script FE-Compatible ?

function waitForChild(parent, childName)
	local child = parent:findFirstChild(childName)
	if child then return child end
	while true do
		child = parent.ChildAdded:wait()
		if child.Name==childName then return child end
	end
end

-- ANIMATION

-- declarations

local Figure = script.Parent
local Torso = waitForChild(Figure, "Torso")
local RightShoulder = waitForChild(Torso, "Right Shoulder")
local LeftShoulder = waitForChild(Torso, "Left Shoulder")
local RightHip = waitForChild(Torso, "Right Hip")
local LeftHip = waitForChild(Torso, "Left Hip")
local Neck = waitForChild(Torso, "Neck")
local Humanoid = waitForChild(Figure, "Humanoid")
local pose = "Standing"

local toolAnim = "None"
local toolAnimTime = 0

-- functions

function onRunning(speed)
	if speed>0 then
		pose = "Running"
	else
		pose = "Standing"
	end
end

function onDied()
	pose = "Dead"
end

function onJumping()
	pose = "Jumping"
end

function onClimbing()
	pose = "Climbing"
end

function onGettingUp()
	pose = "GettingUp"
end

function onFreeFall()
	pose = "FreeFall"
end

function onFallingDown()
	pose = "FallingDown"
end

function onSeated()
	pose = "Seated"
end

function onPlatformStanding()
	pose = "PlatformStanding"
end

function moveJump()
	RightShoulder.MaxVelocity = 0.5
	LeftShoulder.MaxVelocity = 0.5
	RightShoulder.DesiredAngle = 3.14
	LeftShoulder.DesiredAngle = -3.14
	RightHip.DesiredAngle = 0
	LeftHip.DesiredAngle = 0
end


-- same as jump for now

function moveFreeFall()
	RightShoulder.MaxVelocity = 0.5
	LeftShoulder.MaxVelocity = 0.5
	RightShoulder.DesiredAngle = 3.14
	LeftShoulder.DesiredAngle = -3.14
	RightHip.DesiredAngle = 0
	LeftHip.DesiredAngle = 0
end

function moveSit()
	RightShoulder.MaxVelocity = 0.15
	LeftShoulder.MaxVelocity = 0.15
	RightShoulder.DesiredAngle = 3.14 /2
	LeftShoulder.DesiredAngle = -3.14 /2
	RightHip.DesiredAngle = 3.14 /2
	LeftHip.DesiredAngle = -3.14 /2
end

function getTool()	
	for _, kid in ipairs(Figure:GetChildren()) do
		if kid.className == "Tool" then return kid end
	end
	return nil
end

function getToolAnim(tool)
	for _, c in ipairs(tool:GetChildren()) do
		if c.Name == "toolanim" and c.className == "StringValue" then
			return c
		end
	end
	return nil
end

function animateTool()
	
	if (toolAnim == "None") then
		RightShoulder.DesiredAngle = 1.57
		return
	end

	if (toolAnim == "Slash") then
		RightShoulder.MaxVelocity = 0.5
		RightShoulder.DesiredAngle = 0
		return
	end

	if (toolAnim == "Lunge") then
		RightShoulder.MaxVelocity = 0.5
		LeftShoulder.MaxVelocity = 0.5
		RightHip.MaxVelocity = 0.5
		LeftHip.MaxVelocity = 0.5
		RightShoulder.DesiredAngle = 1.57
		LeftShoulder.DesiredAngle = 1.0
		RightHip.DesiredAngle = 1.57
		LeftHip.DesiredAngle = 1.0
		return
	end
end

function move(time)
	local amplitude
	local frequency
  
	if (pose == "Jumping") then
		moveJump()
		return
	end

	if (pose == "FreeFall") then
		moveFreeFall()
		return
	end
 
	if (pose == "Seated") then
		moveSit()
		return
	end

	local climbFudge = 0
	
	if (pose == "Running") then
		RightShoulder.MaxVelocity = 0.15
		LeftShoulder.MaxVelocity = 0.15
		amplitude = 1
		frequency = 9
	elseif (pose == "Climbing") then
		RightShoulder.MaxVelocity = 0.5 
		LeftShoulder.MaxVelocity = 0.5
		amplitude = 1
		frequency = 9
		climbFudge = 3.14
	else
		amplitude = 0.1
		frequency = 1
	end

	desiredAngle = amplitude * math.sin(time*frequency)

	RightShoulder.DesiredAngle = desiredAngle + climbFudge
	LeftShoulder.DesiredAngle = desiredAngle - climbFudge
	RightHip.DesiredAngle = -desiredAngle
	LeftHip.DesiredAngle = -desiredAngle


	local tool = getTool()

	if tool then
	
		animStringValueObject = getToolAnim(tool)

		if animStringValueObject then
			toolAnim = animStringValueObject.Value
			-- message recieved, delete StringValue
			animStringValueObject.Parent = nil
			toolAnimTime = time + .3
		end

		if time > toolAnimTime then
			toolAnimTime = 0
			toolAnim = "None"
		end

		animateTool()

		
	else
		toolAnim = "None"
		toolAnimTime = 0
	end
end


-- connect events

Humanoid.Died:connect(onDied)
Humanoid.Running:connect(onRunning)
Humanoid.Jumping:connect(onJumping)
Humanoid.Climbing:connect(onClimbing)
Humanoid.GettingUp:connect(onGettingUp)
Humanoid.FreeFalling:connect(onFreeFall)
Humanoid.FallingDown:connect(onFallingDown)
Humanoid.Seated:connect(onSeated)
Humanoid.PlatformStanding:connect(onPlatformStanding)

-- main program

local runService = game:service("RunService");

while Figure.Parent~=nil do
	local _, time = wait(0.1)
	move(time)
end

This is a script that turns the new animations into the old roblox animations , It doesn't work when FilteringEnabled is true. It is a LocalScript , If I were to make it a normal script , what would I have to change?

So, with FilteringEnabled, you need something called a RemoteEvent. Which is basically the important component to most FE games. Though, you're gonna have look through tutorials or examples.

Make sure to look at OnClientEvent and OnServerEvent.

OnServerEvent is when the Client (user) is firing it. Like for example, if you were doing a TextButton, you'll use OnServerEvent since the Client is firing it.

But, with OnClientEvent, it's just the oppposite.

Just make it a normal script. You wouldn't need to change anything.