I made a script for a enemy AI. but i have gotten a few errors...?

Here I Corrected Your Code. Comment If It Doesn't Work. I Edited It You Did Not Run The Function When The Person Clicks.

local Zombie = game.ReplicatedStorage:FindFirstChild("Zombie")

local Attack = Zombie.AiScript

local Humanoid = Zombie.Humanoid

local Player = game.Players

local Players = Player.LocalPlayer.Character

local Clicker = Zombie.ClickDetector

local function Attack()
    if Humanoid.Touched:Connect() then
        Player.Humanoid.Health = 0
    else
        if Player.Humanoid.Health == 100 then
            --Your Other Function Here
        end
    end
end

local function Clicked()
    if Clicker.MouseButton1Down:Connect() then
        Zombie.Humanoid.Health = 0 
    else
        if Zombie.Humanoid.Health == 100 then
            --Your Other Code Piece Here I Guess
        end
    end
end