Need some help knowing where to start with all of this, please.

Hi all. This is my first post here and I need a little help. So here are some basics. I'm 5'3", 18 years old, and I weigh 160 pounds. I'd like to get back down to 130. I go to the gym whenever possible and I run on the treadmill, elliptical, etc. I'm changing my eating habits as well. I want to set a number of pounds to lose a week. What's a reasonable amount to lose? Is 5 too much? Too little?