You can start by taking a college course like:
- Level 1 Certificate in Skills for Retail
- Level 2 Certificate in Retail Knowledge
This would teach you some of the skills needed for the job. Then you can try to find a trainee position.
You'll usually need:
- 2 or fewer GCSEs at grades 3 to 1 (D to G) for a level 1 course
- 2 or more GCSEs at grades 9 to 3 (A* to D) for a level 2 course