Scholastic has several free non-fiction stories that you can read and then complete the activities.
This is really helpful because it has the text to speech feature so if you come across a word you don't know, the program will read it to you.
Each grade level has 4 weeks of non-fiction stories to read and activities to complete.
5th grade: https://classroommagazines.scholastic.com/support/learnathome/grades-3-5.html
6th grade: https://classroommagazines.scholastic.com/support/learnathome/grades-6-12.html