What’s the BEST Study Guide for the California Contractor Exam?

I’m preparing to take the California contractor license exam and looking for solid study guides or resources to help me pass. There’s a lot out there books, online courses, YouTube videos and I’m not sure what’s actually helpful or just fluff.

If you’ve taken the exam recently, what did you use to study? Any specific guides, practice tests, or apps you’d recommend? Also curious about how difficult the exam actually is and what surprised you during the process.