Commuting in Malaysia is fairly easy, there is a public train (KTM) and it's the cheapest way to get around. It is not the most organized train system we used, but it does get you to where you need to go. Starting in Padang Besar we hopped on the train, stopped a few days in Arau, Alor Setar, Ipoh, and ended in Kuala Lumpur.
Search more routes online. When in doubt, Uber. That saved us so many times in southeast asia!