Here is an Autobiography assignment that I use in my grade 8 classroom. It can easily be used in any middle school class. It could even be used in grade 9.
The assignment is a lengthy one! It asks the students to write an introduction, a conclusion and then one paragraph for each year of their life. Students are also asked to answer Life Questions (most important person in your life, trips you've taken, goals you have, hobbies, pet peeves, etc) throughout the autobiography.
It comes with a step step writing process, a detailed assignment explanation and a rubric for marking!