[jyl]

Select the whole area, click in menu Data | Sort, then specify which column to sort by and ascending or descending. If your table has a header row, specify that, otherwise specify by column letter.

"Whole area" means all the cells in each row. Any cell outside of the selected area will not be sorted with the rows in the selected area.

First save the workbook, so if you mess up the last saved version is still good. If you have autosave enabled, then play it safe and rename the workbook before re-learning how to sort.