Is there a way to delay the "Touched" event?

Sure, use a debounce. I like using tables because then the debounce time corresponds to each player and the last time they touched that npc, rather than a variable that changes everytime the npc is touched.

local NPC = script.Parent
local RootPart = NPC:WaitForChild("HumanoidRootPart")

--[[
local touchedLast = {}
local debounce = .5

setmetatable(touchedLast, {
	__index = function(self, key)
		-- if the player isn't in the table, set and return their new index
		self[key] = debounce
		return self[key]
	end
})

RootPart.Touched:Connect(function(part)
    if not part.Parent then return end
    local player = game.Players:GetPlayerFromCharacter(part.Parent)
	if player then 
		local index = touchedLast[player.Name]
		-- if the last time we touched the npc is more than whatever debounce is
		if (tick() - index) >= debounce then 
			-- update the last time they touched it
			touchedLast[player.Name] = tick()
		end
	end
end)
--]]

-- Basic way people do it. 

local debounce = true
local bounce = .5
RootPart.Touched:Connect(function(part)
    if not part.Parent then return end
    local player = game.Players:GetPlayerFromCharacter(part.Parent)
	if player and debounce then 
		debounce = false
		print('do something')
		wait(bounce)
		debounce = true
	end
end)