There is this very well-known song by Echosmith that goes "I wish that I could be like the cool kids, 'cause all the cool kids they seem to fit in." There is not one teen that I have met or had the pleasure of knowing including myself, that did not think exactly like that lyric at some point of their life. The cool kids are the most reputed gang in class, no one dares to put them down, they are extremely hyped and everyone wants to be their friend. They are similar in many ways and do a lot of things together. If you want to be with them, you got to be like them, act like them, follow them. No sense of popularity is important enough to lose your individuality over.
Those kids might look cool from afar, but you never know what goes on inside. It's exhausting to maintain a reputation once you are popular. You can't slip up and under no circumstances can you look bad in front of people. You can't stumble, you can't laugh too loudly, you must be "perfect" and robotic. Others seem to follow and copy these "supposedly" cool kids and join the ignorant bandwagon. Being accepted and liked by everyone is not you motive in school, do not work yourself up about it. You are under enough pressure, what with keeping relationships and balancing studies, why do you want to unecessarily add more to it? Attention is sought aggressively during one's teen years and popularity is worshipped with devotion, however none of these is particularly worth it. You get jealous and you try your hardest to "rock" with the general crowd, but for what? Once you leave high school or college, everyone is going to forget about the "it" group. The world will not take your popularity into account when they read your resume. As an adult, you will not stand out by how well you obeyed the rich kids in school, but by how well you can think for yourself and work on what is unique in you.
Believe is yourself as confidently as you do in those popular kids. Those people become like gods to you because you define them to be that way. Why must you give so much significance to someone you barely know? Why must you blindly do things to appear as "accepted" as they are? Looking for reassurance in other people is toxic. People change their minds in seconds, so your source of reassurance is extremely fragile. You must be your sole source of reassurance. You are accepted when you accept yourself. You become cool when you stop depending on people to tell you how cool you are. You become popular when you become confident in the way you are. Your quirks and flaws may not match with the trends, but trust me, they will turn out to be the most precious thing about you with time. Why exactly would you want to "fit in" when you can stand out?