Hiya Pink!
I'm really sorry it took so long. Hectic life stuff--friend's really sick, been having to get my guy ready to go on deployment...fortunately that's over, so here I am! Finally, right?
So I'll do the prologue first, then the chapter.
Anyway. I liked the prologue quite a bit. Pretty whimsical--and a butterfly! I'm interested. The first bit definitely hooked me. The "get jiggy with it" line made me laugh and wonder if these characters really know how the humans are, whether they keep up with them as closely as they might want to. It sort of shows an old-fashioned naivety, and I hope that's what you were going for.
There are a few nitpicks:
The midnight breeze brushed through the dark forest and Danaus’s heart was beating>Try a stronger verb here--pounding, palpitating, racing? with excitement. He could feel the ground whisper secrets to him already and he smiled, watching his hunched mentor finish the rune that displayed itself brilliantly in the air. The symbol glowed the same hue of the moon and gave off a warm yet bone chilling aura.
From his lean back(no comma) sprouted large orange and black butterfly wings and two long thin black antennas sprung from his head.
I like the description you have in here. Really good start. I'd suggest grabbing Ye Olde Thesaurus and spicing it up a bit. Also, watch your past/present tenses and commas. If you need further help, let me know.

Now, to the chapter!
Honestly, it threw me off a little bit. You started with this really interesting prologue, and then I find myself stuck for the majority of the plotline in a high school. There's not much of a transition to tell how these two things are connected. Anyway. Let's see what we've got here.
I pointed at Mark with my finger. >This is weird; "with my finger" doesn't seem necessary, because usually pointing is with a finger. “You get your facts straight, little man. I’m not dating Justin because he’s popular or because he’s rich. I really do like him, okay?” I was tired of people assuming I was some sort of gold digger or a whore. Justin might be the school’s hottest guy and I might be the school’s bad girl but I think we were meant to be, right? >"...right?" That's what you're telling the reader, so that's not really necessary. And I'm going to put this out here: how are they "meant to be?" You continue to say that they are, but you don't seem to give the reader any reason why they would be. Seems like you've got two totally different people who seem, at this point, to have nothing in common, meant for each other. A little building upon this idea is required.
Justin, my boyfriend for over a month and a half,
...and then...
I just had to be understanding and that’s why Justin and I survived all this time.
Hm? That's not really such a long time. What exactly did they survive? It needs to be a little more believable.
I went into my room and took a quick shower. I changed into a pair of leather skinny jeans and a loose grey top. I looked into the mirror and put on my make-up. I always wore dark make-up, it made my green eyes look more appealing and my rose-colored lips never needed lipstick so I just added some gloss so they looked shiny. I then combed my wavy black hair, which I had died a few months ago. I looked at my scalp and I could already see the brown roots that meant I had to dye my hair again. It was a good thing my hair was brown, no one could really notice.
A pet peeve: a large dump about how the character looks. The magic formula is to pepper small details throughout the work to describe how someone looks; doing it like this really takes away from the focus of the story. Even if it is to describe that she's putting on makeup. You could just say something like "I ran a comb through my hair and then carefully put on my trademark dark makeup." That way it's not such a detail-dump.
“Mel!” Carla bounced over towards me. She held onto a plastic cup and I knew exactly what that was. “Oh my god, you have to see Sean, he’s like doing this thing with the pillow-”
Aww, I wanted to know what he was doing with the pillow. 
There he was, pants unzipped and shirt off with that tall blonde girl I had seen earlier. They were on his bed and she was straddled over his lap and her front shirt >shirt front? was unbuttoned.
Hm. I agree that the ending of it was quite predictable; I saw it coming when the party was mentioned, really.
I didn't correct the problems that have already been touched on, but the advice of the reviewers before me is good. I'd take that too.
One thing I see here, also, is that the characters seem a bit flat. Actually, I like Carla the best--she seems like she has the most personality. I'd suggest making character outlines and sprucing them up a little.
So, this seems like it could be pretty good, all things considered. Just needs some clearing up as to how it's related to the prologue, so maybe you should put something at the end, or somewhere, really, to clarify that. Also, just a few tweaks are all you need. Nice job.
Take care, and keep writing!
~Freyja