How do you wear your school bag on Disney superbia

You have to buy it first, but when you have bought it it will be in your inventory. The smiley face with a pencil at the bottom of your selection screen is your 'edit character section. Then click on that and go to accessories. If it is not there, try upper body. Selection. Hope this helps!
My share code is Seahorse413 Add me!!!

This is true, but if you don't care about the bag you have, you can just choose from one of the free bags there is already in accessories.
My Share Code is:
595Jelly481
That is all!