Formula Help Request

It is not difficult, you need to first modify the formula in D1. In D1, use the following formula:

=IF(C1<>"", C1+2, "")

This formula can help you check if C1 is not blank. If C1 contains a valid date, it will add two years to the date. If C1 is blank, D1 will be blank, too. For your other questions about conditional formatting:

when C1 "does not contain blank", C1 cell is green
       1. Select C1.
       2. Go to the Home tab > Conditional Formatting > New Rule.
       3. Choose "Use a formula to determine which cells to format".
       4. Enter this formula:

        =C1<>""

        5. Set the formatting to green.

when D1 "does not contain blank", D1 cell is red
        1. Select D1.
        2. Go to the Home tab > Conditional Formatting > New Rule.
        3. Choose "Use a formula to determine which cells to format".
        4. Enter this formula:

        =D1<>""

       5. Set the formatting to red.