Jennifer wrote...
Why do the cells in Excel sometimes appear blank but in the function line it
shows that it has info in it?

Simplest way: type 1 or more spaces into a cell. If there doesn't
appear to be even spaces in a cell, but Excel treats the cell as
though it contains something, this can happen when cells with formulas
evaluating to "" are pasted as values into other cells.

You could use conditional formatting to visually identify cells
containing spaces or zero-length strings using the condition formula

=AND(ISTEXT(A1),LEN(TRIM(SUBSTITUTE(A1,CHAR(160)," "))=0)

and setting the background color to something unusual.