Ive worked in recruitment before so I can give you a few ideas.
The resume is the main screening device for most employers which means they use it purely as a tool for determining who to ask in for an interview etc so it can be good to have a good resume, or at least one the speaks to the employer.
Think about what the job is, and think about what skills they would be looking for. For example if you are applying for a job in retail (given your age this might be appropriate) think about what retail stores would look for. Usually it would be things like interpersonal skills, ability to communicate and work within a team. Subsequently you should try and find things youve done in the past that demonstrate these abilities.
Dont put down everything youve ever done. Dont tell your employer what primary school you went to for example. This is irrelevant and a prospective employer does not care. Another big mistake might be focussing too much on your school marks. The kinds of jobs you would be going for, marks would not be relevant to an employer.
The most valuable thing an employer would look for is prior experience similar to your current job. If you dont have any, then consider other things you have done that are similar to paid work. Volunteer work, leadership positions, extra curicular activities can all provide evidence of certain skills.
