No, the cheerleading doesn't start (or even get mentioned) in the first episode. But it does a good job of setting up the characters and situation. It gives a grim, but realistic look at life as a lower achieving, poorer student in a very competitive (academically) school. It's shockingly well written, though no without their cheesy drama moments. It's also quite an emotional episode, showing the main character, Yeondu, hit rock bottom, setting up that she has nothing to lose and the only way is up. It really set up my interest in seeing more!