Use the General tab to set a name and optional ID for your grid.
The name is not actually shown anywhere on your website. It just makes it easier for you to remember what this particular grid is for.
The ID is completely optional and will be used in the shortcode instead of just a number if you have one set. For example, your shortcode would now look like [wpupg-grid-with-filters id="photos-grid"] instead of [wpupg-grid-with-filters id="123"]. This could make it easier to identify.