What I learned going through this is that when it's time you will get what you need next - and that's it. They rarely drop the ball in the training department. When you get your CPT enrollment, ATP (not Mesa) sends you the Shep Air stuff. Don't get all upset about the method - use the guide and don't study anything else ahead of time. Check your email and READ EVERYTHING - including the attachments. All your questions are answered there.

Study for the nearest alligator. You'll be drinking from a fire hose. Don't worry about systems or flows or profiles until after indoc. The tightest schedule comes between systems and FPT. The minute you finish systems learn the profiles and briefs. Don't worry about flows until sim training starts. FPT - learn the FMS , learn the profiles. They are on the test. Just do one thing at a time. For CPT concentrate on the Shep air stuff so you can pass the ATP test.