This process is only necessary when you have more than one dashboard created.
If you only have one dashboard, it is already your favourite dashboard by default.

To set your default dashboard, go through the following steps:

Step 1: In the upper right corner of your dashboard choose which dashboard you want to set as favourite and click edit.

Step 2: In the edition panel, click on the star at the right of the Dashboard name.

Step 3: Scroll to the bottom of the window and click Save to take over the changes.

Example of how to set your default dashboard: