You want to update the font of an entire workbook.

To update the font of an entire workbook in Tableau, you should use the "Format Workbook" pane. This feature allows you to set and modify the default font settings for the entire workbook, ensuring consistency in font style across all sheets and dashboards. It's a global setting that applies to all visual elements in the workbook, including titles, captions, axis labels, and other text elements.