Alternatively, you can click on the paintbrush in the pop-up format menu that appears when right clicking, then select the cell you want to format. Then click on Format Painter (the little paintbrush) in the upper toolbar on the Home tab.
In Mac OS, you may need to add the Fn key for this shortcut to work. This only selects cells above and below that have data, so it won’t select empty cells. You can use the Ctrl Z keyboard shortcut or the backward arrow in the upper left-hand corner of the Excel window, above the navigation menu.
Ctrl Z: This command undoes the last action you took in the worksheet.
Some of these are universal across Microsoft Office products (e.g., Word, PowerPoint, etc.) but are still very helpful when using Excel.
Here are some shortcuts that you may not be aware of. One of the top Excel tips is getting acquainted with shortcuts. Excel trick 10: Essential shortcut keys and tips