So, I decided to post my first lua script because it helped me a lot to play with mutiples Tibia Clients. It's a really basic script to follow other players.

Commands:

follow "player name"
start
stop

If you are following one player and wants to follow another one, you must stop it first then use the command follow again.

Code:
local target = ""

Module("autoFollow", function(module)
	local player = Creature(target)
	print(target)
	if player:isOnScreen(true) then
		Creature.Follow(target)
	end
end, false)

function onSpeak(chat, msg)
    chat:SendYellowMessage(Self.Name(), msg)
    if (msg == "start") then
        Module("autoFollow"):Start()
        chat:SendOrangeMessage("Console", string.format("Started following %s.", target ))
    elseif (msg == "stop") then
        Module("autoFollow"):Stop()
        chat:SendOrangeMessage("Console", "Stoped following.")
    elseif msg:match("^name") then
		local name = msg:match("^follow (.+)")
		if name then
			Module("autoFollow"):Stop()
			target = name
			chat:SendOrangeMessage("Control", "New player added.")
		end
    end
end

function onClose() end
  
local chat = Channel("autoFollow", onSpeak, onClose)