Yes, have several ideas of something to do IF the teacher hasn’t left plans, BUT

if there are plans, PLEASE follow them. The teacher knows what she/ he wants the students to do. Respect that, even if you think your ideas are better.

Don’t be pals with the students; in fact, you just might have to be on the tough drill sergeant side with some classes. Don’t touch the kids.

Don’t believe everything (or even much) that the students tell you about the way class is run.

Don’t give out the hall pass unless someone is dying.

Do wander around the classroom while the students do their work. DO NOT just sit behind the desk, whether doing nothing, or reading, or worse — knitting or crocheting!

Great substitues are a blessing. Some others, however, will never pass through my door again.

Good Luck

Best of Luck!