Once you have a list of topics for which you need preparation, you will possibly face two challenges.
Find and study documentation and knowledge resources for the topics and,
Find enough practical case studies covering the topics.
You may register for Acquia Academy Courses and take a course in the relevant domain to refresh your knowledge.
A list of courses on Acquia Academy can be found at: https://training.acquia.com/free-training. Depending on your area of weakness, you may wish to take one of the following courses:
Acquia Cloud User Interface
We have also made a list of online resources and documentation for each learning domain in the Study Guide section.
Take advantage of Acquia Tutorials to gain practical experience for this exam:
Deploy Tutorial - Deploy a Drupal 8 application to a production environment.
Getting Started with Acquia Cloud CD Tutorial - Implement continuous integration for a Drupal application on Acquia Cloud.
Learn more about the Acquia Certification Program at https://acquia.com/certification