HIGHLIGHT DUPLICATE ENTRIES
Hey i have a column of p.o. #s that i would like to be highlighted a certain color if someone enters the same # in and column below or above can someone help me figure out how to do this please.
i posted a picture of where the duplicate is and how to format looks
Answers

Create a new column called duplicate, and set it to checkbox to check for duplicate. Use this formula, and convert to column formula:
=IF(COUNTIF([P.O. Number (if applicable)]:[P.O. Number (if applicable)], CONTAINS(@cell, [P.O. Number (if applicable)]@row) >= 2, 1, 0)
Now, use conditional formatting > If duplicate column is 1, then highlight row
Sincerely,
Jacob Stey

your gonna have to explain a little more for me lol im not so up to speed on how to do all of this. how do I make column formula? and when i copied your Formula into the first cell of my new column it didnt work. so which parts of your formula do i need to enter correct values for?

Right click on a cell with a formula, then click convert to column formula.
What is the error that it gives you, after you convert to column formula?
Sincerely,
Jacob Stey

try replacing with this formula:
=IFERROR(IF(COUNTIF([P.O. Number (if applicable)]:[P.O. Number (if applicable)], CONTAINS(@cell, [P.O. Number (if applicable)]@row) >= 2, 1, 0), 0)
Duplicates should show now, and you can conditional format based off of the value.
Sincerely,
Jacob Stey

i still get the same error message

is the Paratheses in my column title messing up the formula?