Work experience isn't just something you do towards the end of your time at school. It's something that you should look to do again when you are in college or university. Work experience is a great way of showing motivation and initiative on your CV and will help you decide if you would like to go into a particular area of work.
Work experience may form part of a course you do at university and can sometimes even lead to the offer of a job. It's really important to see work experience as something that you do not only in school, but after you leave as well.
Your school's work experience coordinator will support you in finding potential placements for work experience. Arranging the placement will be your responsibility, but you may want to ask your parents to help you.