What should you do to avoid cheating in online classes, even if your behavior was unintentional?

All I can really say is try not to think about it because when you're on a computer you're going to be tempted to cheat but that's what they (the teachers/instructors) trying to get you to do because they know they can bust you

Have no other tabs open, be completely focused, do not try to look up answers to quizzes, make sure you have permission to look at notes on a test, if not then keep notes away.