what position?

what position should i play?
i'm 5'8 5'9 amd o, about 170 pounds

RB DB WR SB Pick one..

That probably depend on what age you are at that size. If you are 18 already then what Onknight said , but if you are 14 then you still have more growing to do and are playing in an age braket where other players are still smaller too , so you would have a lot more options depending on what you are good at.