I only studied for Section 1 by reading Construction Documents (Hinze) and the AIA project management pdfs, by reviewing material I didn't understand by googling concepts and asking RAs/RLAs to explain, and by taking the Shake&Bake practice tests. I was only unsure on a few questions, and I passed.
What I found most helpful about Shake&Bake was getting into the mindset of taking an exam again. It's been many years for me and I had test anxiety because of it. The answers may not be all that accurate, but they are a good tool in exercising your brain to try to figure out the logic of the questions. They were also helpful for me because they were a cheap way to gauge which Section I felt strongest.
As for the CLARB sample exams, I only saw pdfs with the CLARB letterhead floating around this group for Sections 3 and 4. At one point, someone had posted a Section 2 sample exam word document, claiming it was CLARB. Unfortunately, it did not include the answer key, so that thread had crowdsourced the answers.