15 and severly need a job, can anyone help?

how can I get a ''job job'' (not stuff like working in my parents business cause they dont have) like in a subway or at a safeway. something like that. Im 15 and I really need a job because I want to save up enough money to rent an apartment when Im 18 because we're a family of 8 and because of the whole crisis thing we'll soon have to move to a one-bedroom apartment. I've never been spoiled. I dont have an allowance and haven't ever had one. I haven't shopped in over a year and we have food-stamps. I've been wanting to have a nice all my life and want to start as early as possible. What are the steps I have to take in order to get a job at 15?