Currently all training material can be found under:
Atlassian training material for Confluence Data Center can be found on the following page: https://confluence.atlassian.com/doc/confluence-data-center-and-server-documentation-135922.html
Add a Code Block macro to your page to display code examples with syntax highlighting.
This is great for sharing code snippets such as:
To add the Code Block macro to a page:
From the editor toolbar, choose Insert > Other Macros.
You can then publish your page to see the macro in action.
More information can be found on the following Atlassian page; Code Block Macro