Affording a car

I'm 18 and female, no GCSE passes, need a join paying job, I want to buy a used car, not expensive, I'm actually more into older cars and doing them up a bit, I really like the x type Jag so if I could afford that or a car like that I would go for it, my problem is I'm in college, I do let sitting but not earning enough, I need a car as I've got friends who grew up with parents not driving and it's an absolute nightmare, I can't rely on public transport for the rest of my life, I'm stupid for failing GCSEs I know I probably never will afford a car as I can't get off minimum wage and I'm only doing level 1 qualifications. What do I do? Don't say a car isn't a priority or important as it is and is expected from me, although my sibling only earns 10 grand a year and can afford a car so I know it's possible but don't know how.