Okay, so, before I comment let me just warn you: I'm very honest.
I'm not really one for fanfics, but for your first story, this isn't too bad. Although it seems like you wrote the first chapter really fast because words are left out left and right. Something you could improve on: the tone. The tone is a little flat. You should try using a variety of words to show the character's personality, especially since it's first person. Cassandra comes across as a little boring.
But thats just a critique for general authors. Good job for your first try, but it still needs some dusting off. Keep writing and practicing, though, because otherwise you can't improve :)