Back to school clothing help & help with Hollister AE Abercrombie A&F sizing?

Hey I'm a boy I'm 13 my birthday is next Friday so I'm turning 14 gonna spend the BD money on cloths (Not including shoes but would like if you suggest some ;) ) I weigh around 130 - 140 lbs I think. I'm 5'0 or 5'1. I was wondering what sizes am I at Hollister,Abercrombie,Abercrombie&Fitch and AE (Everyone says the sizes are different) cause I shop at Aeropostale and my shirt size is a Large and for Shorts I wear a 29 and I don't really wear skinnies but thinking of getting some so wondering if you'd give a range on what size I should buy also I'm thinking of buying one or two sizes bigger on shorts and pants since I don't wanna grow and all my crap wont fit me haha