Taxes (My first job)

[Spy]

I'm a 17 year old American and about to start my first job (I know, i've been lazy up to this point).

I turn 18 in May of next year and would like to set aside a small part of the money I make towards a poker bankroll so that when I turn 18 I can play some online poker without risking much.

However, because i've never had a job before, i'm not sure how much of what I make is going to end up going towards taxes, so it's harder to calculate how much I will be able to put towards this poker bankroll.

This is probably a really easy question to answer, but if anyone can help me figure this out it'd be much appreciated. (I live in Massachusetts, assuming that makes a difference)

Thanks in advance.