After you file

I’m in the same boat, but I made a little over $4000 doing DoorDash in 2020. I’m 20 and classified as a dependent by my family. It’s my first time filing my taxes so I have a lot of questions. According to a lawyer who “specializes” in taxes, I do not need to file since I didn’t meet the $12k threshold but I doubt this since I’m considered self employe. I’m pretty sure the lawyer was referring to those who hold jobs that aren’t classified as self employed. Do I need to file taxes or do I not?