As an administrator, you can make some additional blocks available so that users can add them to their personal dashboard (see Customizing the dashboard).
You first have to create some blocks (in the standard Drupal way, at /admin/structure/block).
Then visit this urlon your Opigno instance: /admin/config/opigno/dashboard
The interface looks as below:
All the available blocks on your Opigno instance will be listed. You can select the ones you want to make available for the Opigno dashboard by checking the option in "Available" column.
In case you want to prevent users from removing one block from their dashboard, you can check the option in "Mandatory" column.