There are many reasons why they buy magazines. Maybe because of their celebrity crush, fashion, boy tips and etc.. Each girl has their own different way.
If your a teenage girl wanting to get a job there are loads out there. Supermarkets are one option. Although for some you have to be over fifteen or so to work there, so check that out before putting...
My favorite game of all, it is perfect for teenage girls, it is called: Get on your knees and open your mouth, it is guaranteed fun for everyone involved!