If I work for postmates, how will filing taxes work?

I was told that I would have to pay all the money back. I know I won't have to pay it ALL but what might I have to pay? And can I get deductions from things like gas and my phone? (I'm not super familiar with tax terms so please try to dumb it down for me). Is it if I make more than a certain amount? I've been doing this part time for about 3 weeks and made $422.