Request for feedback & critique on a novel(la)

(...when is a novel a novella and when is a novella a novel? All I know is the novella is shorter.)

Anyway - hi. I was searching for some kind of site where people could share stories and get feedback, and this is the one I stumbled upon, although I'm not sure if it's the place for me...let's see what happens. (Feel free to laugh and tell me to go somewhere else.)

Basically, I've written a story and would like a bit of feedback from more experienced writers than myself (which means just about anyone here). It's very important to note that what I've written is a story for teenagers written by a teenager (I'm 17), and it's not at all Deep or Meaningful (if you tried to use it in an important English essay you'd get nowhere). My only intention was to write a fun, entertaining youth fiction story.

A few of my friends read it, and they said they really enjoyed it, but of course they'd say that - they're my friends! I know myself it's not brilliantly written and full of flaws, but I'm not sure how to fix them. I would love some honest constructive criticism so that perhaps I could re-shape my story to the point where a publisher wouldn't just laugh in my face.

Full story here: solitaria-story.blogspot.com

If you do give it a read, regardless of whether you liked it or not, please let me know!