How to respond: Your friend tells you to throw your food at another friend?
Say "no", food is to eat, not to play.
How to respond: You are going to the bathroom and a classmates tries to go into your stall.
Tell your teacher or other trusted adult.
How to respond: You are in line waiting for your teacher and your friend gives you a slap on the back that hurt.
Tell your friend to stop because you don't like that.