Note that your question does not specify what happens if B4 is equal to B3, so the following assumes it is left blank:
=IF(B4>B3,"Y",IF(B4<B3,"N",""))
If Y is for greater or equal to:
=IF(B4>=B3,"Y","N")
If it is N for equal to and Y is only for greater than:
=IF(B4>B3,"Y","N")
You use the "IF" function.
The NOW function
Once the cell is selected, then you can just start typing. See the related question below.
worksheet
Cells are the fundamental element of a worksheet. All formulas are put into them. Most functions and formulas will reference cells on the worksheet. So cells are extremely important in Excel. Without them, you do not have a worksheet.
You can type notes directly onto the worksheet, you could type them into a text box on the worksheet, or you can add comments, which are attached to a cell. Pressing Shift - F2 will enter a comment into the selected cell. A small red triangle in the top right corner will indicate that a cell has a comment and it can be seen by putting the cursor over the cell.
If you select one cell, it will be active. However, if you select multiple cells at once, only one can be the active cell. That is usually the cell you select first.
Each program has its own formula, one should look for the tutorial on the program one is using in order to know the correct way for each separate program.
Click on the extreme upper, left hand cell, the whole sheet is selected. That way U also select, whichever cells that are filled.
NOW function
The cell borders are highlighted, or if a range of cells are selected, the active cell will be a different colour than the others, usually being white. The name of the active cell will always appear in the name box.
false