I am applying for a job at No frills as a cashier? Am i old enough?

I am 15 years old and in grade 10, I really want this first job. I am turning 16 in August and I can't wait till then to work! Does anyone have any experience working as the cashier at 15? I think i am under age but i am willing to try! I really need the money right now because I want to be independent and my father is planning to retire so, i need a job ASAP! I feel that i am pressured to find a job because of my family but i really want to make them happy. I am not willing to work at fast food chains, I prefer to work at grocery stores or department stores but they are not hiring right now and I really want a job before summer hits.