How to select an entire row or column in a spreadsheet
To select an entire column or row in a spreadsheet, click on the column header or row header. For example, if you clicked on the "H" column header (marked in red in the picture below) the "H" column is highlighted. If you clicked on the "16" row header (also marked in red), the 16th row is highlighted.
Once a column or row is highlighted, you can apply any properties or changes that can be done to an individual cell. For example, once an entire column is highlighted you can click the center text icon to center all text in that column. You can also press the delete key on the keyboard to delete all highlighted content.