Get the facts on the types and levels of information that the Network Health page provides, the organization and layout of page features, and the general navigation and functions that you can use to access the information that you need.
Review Navigating Assurance Network Health, which is a PDF-formatted file.
The Table of Contents is a great place to start, posing the questions that you are already asking!
When you are finished, take a look at other Cisco DNA Center training opportunities.