Transaction Cycles

This is mostly a rant post about how tricky transaction cycles are. Every one of the lessons I’ve done in my study platform , I scored around 50’s on the assessment portion and I usually never score low so I know this will probably be a weak area of mine. I hated learning transaction cycles in my accounting information systems class in college and I hate them now lol. The questions are so tricky and separation of duties has me particularly confused most times. Anyway two questions.

1. Is this highly tested? (I assume yes)
2. Any resources that have good explanations about the transaction cycles and control activities?

Thanks.