I joined Pega approximately 15 months ago with no hands on Pega experience.  The CPBA certification and testing is heavily focused on the theory of what the standard BA should focus on.  I suggest you focus on the training materials provided and know them inside and out v being concerned with the technical aspects of Pega.   I found creating and reviewing flashcards as being very helpful.  The training materials and certification do indicate what % of the questions will come from each component of the course; ex; Case Lifecyle 32%.  As an FYI this certification continues to evolve.  I just looked at it and the Business Product Automation is a new, and very important, section to the training.  All the best