Sorting by columns in spreadsheets is easy. First, find the bar which separates frozen rows from unfrozen rows (by default, there is one frozen row, so this bar will be right below the first row -- if you have changed the number of frozen rows, it might be in a slightly different location). If you hover your mouse over that bar, a section of it will turn orange and have the word "Sort" on it. Click the downward-pointing triangle to the far right of the column and choose either A-Z or Z-A. The contents of any row above the sort bar will be unaffected by the sorting, allowing you to preserve column headings if desired.
Note: If you wish to sort first by one column, and then by another (for instance, by last name and then by first name), first sort by the column of secondary importance, and then by the column of primary importance.