The first ~10k you make is taxed at 10%
In the USA, technically the first $15,000 (if single) or $30,000 (if married and filing jointly) at least is taxed at 0% due to the standard deduction. If you earn less than that, you can tell your employer that you don’t want any tax to be withheld.
I’ve heard it in Australia too, which has the same tax bracket system as the USA. I think the fact that this stuff isn’t taught in school is a major issue.