how can i make it so the script activates only when the part is touched?

Code:

local part = script.Parent
local InProgress = false  -- We will use this later to find out if another interval is in progress
local debounce = false   -- Use a debounce to prevent people from spamming it

local function MovePart() -- This is from your code
	for i = 1, 200 do
		part.CFrame = part.CFrame * CFrame.new(0,0.1,0)
		wait()
	end
	wait(5)
	for i = 1, 200 do
		part.CFrame = part.CFrame * CFrame.new(0,-0.1,0)
		wait()
	end
end

part.Touched:Connect(function(hit)
	local player = game.Players:GetPlayerFromCharacter(hit.Parent) -- Get the player from the character
	
	if player then
		if not debounce then
			if not inProgress then
				InProgress = true  -- It is currently in progress
				debounce = true  -- People can't spam no more
				MovePart()   -- Move the part 
				wait(1)
				InProgress = false -- When it's done, make this variable equal to false
				debounce = false -- Now people can step on it again
			end
		end		
	end
end)