Power Clean Question

Hi I am in High School and I do the power clean workout about twice a week. I have 2 quick questions on the technique/form.

1-I see people doing a thing where they kind of pop it off their hips to get height. I tried it like that and failed miserably, when I powerclean it is all one quick motion. I weigh 150 but can only clean 165 by the way

2-I have been told to “Stomp the ground” real hard during the second pull, but how is that possible if you are supposed to get low and under it at the same time? Because stomping will send you up, now down

Thank you very much for your time