How to make people call me a diffrent name?

So, i really hate my name and i want to change it...but not on my ID and stuff cause thats 2 much paper work for me...and i m just 16 so i would have 2 make my parents do it...but they r against it so i just want to have it like a pet name at school and everywhere else...so i just want that everyone calls me that withouth changing it officially...i am changing school this year...i will not know anyone in my new class...so should i introduce my self with my new name or say my name is ...... and tell them 2 call me diffrently after some while....if i say my new name they will get confused and maybe call me by my official name....so what and how should i do?