I can't ollie at all, can you help?

im just learning to skate, and im stuck on the ollie. im practicing it in my room, on my carpet instead of on the streets. i try to ollie, i watched like all of the videos on youtube, but i just cant do it. i dont even think the skateboard lifts off the ground. i know where to put my feet and everything, but how EXACTLY do you ollie? like what do you do first, the stepping on the tail or the sliding of the front foot? and what do people mean by listen to the "pop", whats the pop?