The packet your receive before you start can be helpful but it is NOT what you should be studying once you arrive. All of our instructors told us to throw it away after indoc once when we started systems. I wholeheartedly agree. The AOM, GOM, and systems manual are the gospel and what you will be tested on.

There is definitely a lack of context with the pre training packet so do the best you can with it. Push the "I believe" button on items you don't understand and just know that it will all get cleared up during ground school.

All of the instructors and classes ahead of you want to see you succeed and will go out of their way to help if asked.