To everyone in high school who is introverted or shy, you are not alone. When I first began high school, I had recently moved to a town about two hours away from where I went to school from kindergarten until eighth grade. I was extremely shy and socially awkward, and I didn't know anyone there except for my cousin. My only friend lived two hours away, so I mostly spent that summer by myself.
When I started my freshman year at a school full of strangers, I was scared and didn't know what to expect. I was too afraid to speak to anyone first to introduce myself, but luckily for me, a few people in the same grade saw me sitting alone at lunch and decided to join me. They were the ones who became some of my closest friends for the next four years. Those friends introduced me to their friends, and for the first time in my life I had a decent sized group of people who I enjoyed being around who seemed to enjoy my presence as well. As shy as I am, I was shocked that I was able to find a group of friends that I could be comfortable to be myself with.
Gradually, I started doing things with my friends that I would never have done before. I went to my school's football games just to socialize, I went to class meetings and met several other people who I wouldn't have normally even spoken to.
The way I presented myself changed, too. I started dressing differently, changed my hair, and started wearing makeup. While they may be superficial changes, it does show how I began to grow as a person. The girl who wore bulky clothes and hid half of her face behind her hair in an attempt to make herself unseen became the girl who isn't afraid of others seeing who she really is. After making friends who cared about me and made me feel comfortable to be myself, I no longer felt that I needed to hide. Instead, I felt more confident. I stopped constantly looking down while walking through the hallways, and I eventually talked to people in my classes that I hardly knew without getting nervous.
Right before my senior year of high school, I had to move back to the town I had lived in while I was in middle school. I went from almost always having friends to hang out with to being lonely most of the time. Although, because of the friends who boosted my confidence in the past, I was able to make it through my final year of high school without being too wary of what others thought of me. I kept forcing myself out of my metaphorical turtle shell to make the most out of my senior year, even when my confidence started to waver. I joined the drama club with the one friend I had known for years, kept talking to people and making acquaintances, and I went on my senior trip, even though I feared that I would be the loner in the corner for the entirety of the trip. Surprisingly, I wasn't. I actually ended up enjoying myself and it became one of my best memories of high school, although it definitely would have been better if I had all my close friends with me. I don't regret coming out of my shell and never will.
To any introverts in high school, don't let yourself be the one who never socializes out of fear of what people think of you. Force yourself to do things if you need to. If nobody goes up to talk to you, go talk to someone that you think is interesting. Join clubs or sports if they interest you. If you're afraid to do these things because of potential judgement, the people who will judge you are insignificant and don't matter in your life. Find people that are supportive and caring, because those are the only ones that matter.
Speaking from my personal experience, you will not regret forcing yourself out of your shell. However, you will regret restricting yourself from doing things because of your shyness. You could make friends with people you will be close with for these four years, or they could be your friends for life, or you could only end up making acquaintances. You won't know until you start inching out of your own metaphorical turtle shell. Get yourself out there and make the most out of these four years before you go out into the real world or go to college, because you are the only one who can make the best of your own high school experience. This is helpful for life after high school too, so don't hesitate to try to kick some of your shyness to the curb whenever you get the chance.