As a 15-year-old, you are not expected to have significant qualifications before applying for jobs. Experience you may have from performing childcare for siblings or from a family business is great, but the majority of roles available to you are entry-level positions for which employers are seeking candidates possessing “soft” skills, things like reliability, availability, customer service skills, and a professional attitude. You may need a work permit, depending on the state in which you live, in which case you can ask your parents or school counselors for help; they may also be able to point you in the direction of conscientious employers willing to hire teens.