I can’t answer your specific question with a study guide recommendation but will offer a comment. I took the 15 hr. many years ago and have since taken the 7hr updates every two years, as required. Over the years course developers seem to struggle to make that material seem relevant (though it is). Most seem to settle for prodding the students awake. It has been a while since I took an in-person class which may benefit from the instructor’s skills or personality, even. Online classes have numerous prods. And students complain about them.
What I find makes more sense than the instruction, is the document itself. Sit with a hard copy and read. Read the bold parts of Std 1, then go away. Come back and read it again but with all the text.
It is not an attractive document, but you can see the structure they use to convey the information. If it helps, sketch yourself a diagram. (Some people are visual thinkers and that helps with any text.)
Std 1 is about development of the appraisal. It is process. Then move on to Std 2 and see how it corresponds with Std 1. Std 2 is about how you transmit the appraisal you developed according to Std 1. It is about delivering your results.
They have made some changes over the years. A while back, a big one, Scope of Work. But really, years go by with them just clarifying, going for consistency. It is a good thing, if not exciting. They recently applied the same Std1 development and Std2 reporting structures to later Stds.
So, go for really getting the difference and meaning of 1 and 2 and then see that they are really repeating those concepts in the subsequent ones and those will move faster for you because you recognize the structure.
Learn by type which added material is considered part of USPAP and which are commentary, as test prep. Good luck with your exams.