Hiya!
Have you tried looking in your local shop? If its a question of experience you could always offer yourself as a volunteer in a charity shop. Think of what you like and what you enjoy and dont be afraid to approach potential employers yourself. Explain that you are young but that just means you are easy to train to their liking and that you are looking for a long term career. The job centre should be able to help you to find something. You could also consider apprenticeships?