How can I make a on touched part slowly rotate a part not connected to the script in the workspace?

Rotation = workspace.Existing1.Rotation.Vector3.new(0, 157.5, 0)

i = -1

Goal = workspace.Existing1.Rotation.Vector3.new(0, i, 0)

script.Parent.Touched:Connect(function(p)
	if p.Parent:FindFirstChild("Humanoid")then
		p.Parent.Humanoid.WalkSpeed = 0
	end
	do Rotation + Goal until workspace.Existing1.Rotation.Vector3.new(0, 7.5, 0)
	end
end)

Be aware I am really new to Lua.

I can see traces of other programming languages in that script. So first, you need to know what is the procedure of functions. Like, instead of do thing until thing, in lua, it is repeat thing until thing. Second thing, how to set properties. Third, better ways of doing thigs. Rotation isn't using anymore in favor of CFrame, and TweenService would be a better use instead of repeat until. Here is the script, and I'll link api reference for you, as I can't explain everything here.

local tweenService = game:GetService("TweenService")

local part = game.Workspace.Existing1 -- so you don't need to index it over and over again

local tweenInfo = TweenInfo.new(
	
	1, -- time for the tween to take
	Enum.EasingStyle.Linear, -- easing style, ima link the differences
	Enum.EasingDirection.In -- same for here, though it is the easing direction
	
)

local tween = tweenService:Create(part,tweenInfo,{CFrame = CFrame.Angles(math.rad(-7.5))}) -- put the angle you want 

part.Touched:Connect(function(hit) -- for touched events you normally would use hit as an argument, though it obviously doesn't make any difference
	
	if hit.Parent:FindFirstChild("Humanoid") then
		
		hit.Parent.Humanoid.WalkSpeed = 0
		
	end
	
	tween:Play()
	
end)

TweenInfo TweenService CFrame property CFrame constructor math (scroll down to see math.rad usage) EasingStyle EasingDirection I think that's all. Hope this was helpful.