I had a look at your flickr account and I would agree with the others here that you are off to a good start. If you are really interested in photography, then follow your dreams, study your craft, find a mentor, find some established photographers and see what you like about their work and what you don't like. Read up on composition - have a look at this site and see what they have to say...
Digital Photography Tips and Tutorials , but don't let it overwhelm you. The fact that you have an active Flickr account and were willing to post here looking for comments says a lot about your determination - keep shooting and keep reading - above all practice, practice, practice and experiment, experiment, experiment - don't expect to like everything you shoot and most of all, don't expect everyone to like everything you shoot - everyones tastes are different. I am a serious amateur myself and I have been taking pictures for many, many years and find that I just shoot for my own satisfaction - if I like it, that's all that counts for me, but then I am an amateur and only have to please myself, but, you know what I find...that in pleasing myself, I am also able to please others from time to time and that really is great.
Do you have a photography club at your school? If so, you might want to think about joining it, or even if there is a local photography club that encourages young people to develop their skills in the subject - go to a meeting and find out. Keep up the good work...
Cheers,
WesternGuy