How Can I Convince My Parents to Allow Me to Get a Job?

First things first, please read all, or as much of this as you can, because it's important to know all or most of the details before assuming things.
I'm a sophomore in highschool (only for 3 more months lol), and I don't do anything with my life, expect my hobbies (writing, reading, animating, socializing online, and drawing). I get good grades, and I do my homework (I don't even know how I get it done because I don't do it when I'm home but it somehow still gets done).

I have conservative parents, and they barely let me do anything (and I'm going to be 17 in November). I'm surprised they let me breathe on my own. I think it's more of my dad who's holding me back more than my mom (I think my mom is okay with me getting a job, but it's my dad who's holding me back).

Anyway, I want to get a job, because I'd like to have some pocket money (I don't have an allowance because my parents are too poor for that), save up for college, and maybe a car (I don't care what kind of car it is as along as it works, and since I'm getting my license in a few months, it'd be good to have a car because my parents can't always bring me everywhere like the library).

The only time when I get money is on my birthday and maybe for Christmas. I don't like relying on my family when it comes to money, and I can only go so far with it. My family has barely any money themselves.

A few months ago, I asked my dad if I could get a job, and he said no because I have to focus on school, and it's not appropriate for a teenager to be working with adults (I thought this part of his answer was a little unreasonable). He then asked me why I wanted a job so badly, and when I told him the college part he said he'll pay for my college. I'm like no you won't, because you don't have any money yourself to do that, and my older sister is living off loans (he isn't paying one cent for her college). I didn't tell him that directly, but it's true. The last thing he told me was is that I can start working when I finish college (he's a bunch of BS).

My dad has always been on the safe side. I lost some opportunities because of this man. I'm sorry to say this, but he can't keep me locked up in a house forever to keep me safe. If I don't start working before college, it's not going to look good for me in the future.

I live less than 5 minutes (walking wise) from any place you can think of (restaurants, fast food, pharmacy stores, supemarket, dollar store, a flower shop etc.), so I don't see why it's so bad for me to get a job when I live close to all these places. My parents don't even have to worry about driving me/picking me up.

And out of all of this, after all this BS, he lets me volunteer at the one elementary school from 3:30 PM - 6 PM (but that's only on Thursdays and if you've gone to school, I think you would know that basically every single teacher assigns tests on Friday, and I still do good on them). It's an after school program, and I help them kids with their homework and play with them until their parents come to pick them up. I'm around [i]adults[/i].