Kundalini yoga teacher here. These mantras are Sanskrit which Kundalini yoga uses. You can just do Kundalini yoga and still advance. I'm sure you're referring to the basic spinal series, what this does is raise energy from the Kundalini through your chakra system. It is a simple and powerful set but is not targeted at empowerment of a specific chakra.
If you want the best results vibrate mantras AND do yoga. If you are new I would stick with your kriya and work on visualization of the chakras as taught by JoS. Add mantras when you can easily feel your chakras and the energy flowing through them.