Hello wonderful Salesforce peeps. I need to take the Salesforce platform app builder credential

What is the best site to use as a study guide/ exam prep?

Cause honestly I've been using Trailhead and I feel it's just a big advert for Salesforce and it's so condensed it feels like a beginner course and I'm scared the test questions will be more profound than what is displayed in there.

I am a complete noob in Salesforce but I do have CRM experience, DB experience, Security experience, and programming experience.

Help a Newb