Congratulation Muxanh and welcome to the Forum. No need to add any pucks till you require smoke for smoking. I turn on my puck element without any pucks to help preheat the smoker and to heat up the puck element. No need to add pucks till you are ready for smoking, its cheaper that way, rather than sending smoke up the vent just to preheat your smoker
Take a few minutes and go through the forum and read up on tips and suggestions. If you have any issues or questions someone here will be happy to help you out. Once again Welcome to the Forum.