Daily updated activities from the Book Trust that parents can do with their children at home:
https://www.booktrust.org.uk/books-and-reading/have-some-fun/
https://www.booktrust.org.uk/books-and-reading/have-some-fun/fun-at-home-with-authors-and-illustrators/

Activity sheets based around creating your own stories and illustrating them:
https://www.booktrust.org.uk/what-we-do/childrens-laureate/former-laureates/lauren-child/staring-into-space/

Pictures that you can use to write a story about:
https://www.booktrust.org.uk/news-and-features/writer-in-residence/previous-writers-in-residence/chris-riddell/illustrations-in-search-of-a-story/

Audiobooks from the World Book Day charity for children to listen to:
https://www.worldbookday.com/world-of-stories/

Video activities with authors that children can access at home:
https://www.worldbookday.com/online-masterclasses/