I'm a 20 year old woman, this is my benchpress routine?

That sounds pretty good. I mean, I'm assuming you aren't trying to bulk up, so a routine like that is more geared towards endurace/small strength gains/and muscle hypertrophy. Normally people will do 12/10/8 or 8/6/4, but as long as you are challenging yourself with your rep ranges you can set them however you'd like.