Well, while I agree with Will that a shotlist is a very good thing to have, I wouldn't recomend it for the first film! It wasn't that long ago that I made my first film with a decent script, actors ect. We didn't have a shotlist, let alone a storyboard! And I don't think we would've done any better if we had one.
On the first project we learned quite a lot, nevertheless! We had many other things to worry about and I think a tight schedule, storyboards and all the stuff that's great to keep you on track if you make "real" movies would've kept us from just doing it. Planning for ages can be very rewarding, but if it's you first film, I say you just go out and do it!
Don't worry too much about getting everything perfect the first time. Experiment, try what works and what doesn't. You're 17, that's great! That way, I'm sure, you have plenty of time to try out new stuff, make lot's of movies and when the time comes for you to see the real benefit of planning a project very detailed beforehand, you will do so. But not now.
And now you can start making that movie
