High school can be a very hard time for most teenagers, I for one was very shy around new people. However, I eventually grew from the shyness later on in my years. What helped me the most was finding the right extra circular activity, although most of the activities around school were not of my interest I found the newspaper and yearbook fascinating. I was able to work as a Sports Layout editor and photographer. I developed most of my pictures in the dark room, when we didn't have to rely on digital at the time. I set up my own pages for the yearbook, which I found to be the highlight of my final year in high school.
When you're in high school to get through the four years is to concentrate on your educational goals, hang out with your closest friends, be yourself and attend more of the school events. So when it comes down towards the end of those years you'll feel like you've accomplished so much you'll be ready for college.