You could take a college course like a Level 2 or Level 3 Diploma in Painting and Decorating. This will teach you some of the skills you'll need and may help you to find a job as a trainee with a decorating company.
You'll usually need:
- 2 or more GCSEs at grades 9 to 3 (A* to D) for a level 2 course
- 4 or 5 GCSEs at grades 9 to 4 (A* to C) for a level 3 course