Gmail in the classroom - substituting

I do not have a regular classroom but I only substitute in the same small school district.  Each student and faculty member have their own Gmail account.  It would be nice to receive the lesson plans by Gmail.  Perhaps the day before, if possible, so I could ask questions of the teacher.  I can also see how teachers can give assignments by class or even a smaller group.  Currently, our high school has 1 to 1 technology/macbooks with the students.  Often assignments are given over a program called Canvas.  Middle school students do not have laptops, but are often on computers at school or home.  By sending assignments out over Gmail, the students could never lose the assignments and even parents could have access.  The labels and filters would be very helpful in keeping teachers and students organized.