Hi,
First, you need to understand that there are different levels of certifications for different products. So, you would have to go step by step. For example, if you need to target the AEM Architect exam first, then you could target the Adobe Analytics Architect exam, and so on. With that in mind, I think the best available source is the official Adobe guide, which exposes topics and suggests links to documentation and training. Some of these resources are paid. Also if you are an Adobe partner, there is good material to take advantage of under the Training section.
Overall, in my experience, passing the exam is not just a matter of studying but also hands-on experience. Good luck!
Resources:
- Adobe Certification Home: https://experienceleague.adobe.com/docs/certification/program/technical-certifications/aem/aem-overview.html?lang=en (here you can choose which cert you want to give it a shoot).
- Solution partner Training page: https://solutionpartners.adobe.com/solution-partners/home/learn/enablement/training.html
Hope this helps