Access this website for lots of reading book aimed at your child's reading level. You can check their reading level by looking at their current reading books at home or via Active Learn. E.g pink, red or yellow.
You can also access https://www.activelearnprimary.co.uk/login?c=0 to access reading books allocated to your child. The login information was sent via Parentmail or in the back of your child's reading diary.