how to learn fivem esx scripting code example

Example: fivem esx script

// Initializing ESX and PlayerData
ESX = nil
playerData = nil
Citizen.CreateThread(function()
	while ESX == nil do
		TriggerEvent('esx:getSharedObject', function(obj) ESX = obj end)
		Citizen.Wait(0)
	end
	playerData = ESX.GetPlayerData()
end)