Your parents should have bought you a car four months ago?!
I'll tell you a little bit about how I started working. It started when I was 10 or 11. My grandfather owned a shoe store for all his adult life. When I was 10 or 11 I got to start helping him prep for floor shoe sales. I meant to use the word "got". It was a privilege. It was sort of a right of passage to get to start helping grandpa with his shoe sales. He paid his grandkids well, but you better keep up with him as he was writing out the sale prices on the tags and you came behind and stapled them on and folded them over. As I got older, I spent some time in his shoe store helping him. He didn't really need the help. I'd do little odd jobs for him as well as help customers. The elderly ladies were a chore. They'd come in and try on 13 different pairs of shoes and then not buy anything. I'd have to help them select the shoe, find it in their size, lace it and physically put it on their feet and tie it. They'd not like that pair so I'd get another for them and do the same routine over and over. They were difficult customers. Their feet would maybe be a bit stinky and not exactly a pleasure to work with and they were picky. Looking back, my grandfather didn't need a bit of help from me at his store. He'd just have me help out at the store so he could teach me good work ethic and customer service.
I also mowed his lawn. Again, he'd pay us well, but we (myself, my brother and cousin) had to cut it straight and pick up twigs and trim around the house and trees and such really well. When we didn't, he was disappointed. When I was 14 I started mowing lawns for several people and a business. I couldn't drive so my parents drove me around and dropped me off (or helped as well) and when I was done they'd pick me up. I didn't make a ton of money, but it did add up. I didn't realize then what a sacrifice that was for my parents. They had worked all day and then spent their evenings not relaxing but running me around so I could use their lawn care equipment and make a few bucks and teach me work ethic and discipline. For a while I worked part time at a bank. I pulled weeds and picked up trash for an hour or two each day. Later on I got a job at a grocery store bagging and then moved up to checking. I worked at some stockyards at the same time. Came home covered in elephant dung from cows, pigs and goats every weekend. Then I got a job at a quick lube place. I left there to go to work for Walmart. Every job I worked I gave it my all and was great at it. Within a year of working for Walmart I moved up and was salaried and made good money for a 19 year old kid. Over ten years later I'm still working for Walmart and make great money, have moved up several times and have a great career.
I bought my first car when I was 15. My parents didn't buy it for me. In fact, I paid cash for it. A 15 year old paying cash for a car... I busted my ass. I paid attention, I learned lots, and I was great at everything I did. You need to first excel at school. Get those Fs up. Then think about working. If you want a car, work for it. Don't think you're entitled and your parents should buy you one. Get a job, whatever that job might be and don't be picky. Whether it's mowing lawns, shoveling elephant dung, sacking groceries, stapling shoe tags or whatever. Be the best lawn mower, elephant dung shoveler, grocery sacker or shoe tag stapler you can be. Pay attention, because what you learn at this age will shape you into what you'll be for the rest of your life. That doesn't mean that if you start out sacking groceries that's what you'll do for the rest of your life, but what you learn there will carry over to other jobs and your future career.