Google Sheet Conditional Formula for IF function - if-statement

Trying to make a Google Sheets Formula for Conditional Formula that when a cell in column "A" is equal to then change the background to red if Cell in the matching row in column "E" is empty
I started with REGEXMATCH but I couldn't figure out how to format it.
Basically, if the company's names match they require a PO# in which it would mark the cell red if not filled out

try:
=($A2<>"")*($E2="")
apply it on range A2:A

Related

Google Sheets Arrayformula with some sort of concatenate/textjoin/something similar for all rows

I'm trying to do an arrayformula that goes down all rows. I want it to grab the text from a specific row if the row that it's on meets conditions.
Here's an example of what I'm trying to do: have a formula in G5 that iterates through A:F. If the cell = "N", the grab the text from row 4 and concatenate it into a single string, with the text separated by commas.
I've looked at other questions on stack overflow but they're not quite the same.
Here's a sample Sheet
I've gotten as far as the formulas in K4 and P4, but can't figure out how to make it all one formula.
Any suggestions on how to do this?
use:
=ARRAYFORMULA(REGEXREPLACE(TRIM(FLATTEN(QUERY(TRANSPOSE(
IF(A5:F="N", A4:F4&",", )),,9^9))), ",$", ))

Google Sheets: Find match, check for text in adjacent cell to matched cell

Example data here.
I'd like to use conditional formatting to highlight cells where, if the cell's number is found in another sheet, and there is text in an adjacent cell, it is highlighted.
So, given Sheet2:
When a B-column cell in Sheet1 matches an A-column cell in Sheet2, it checks if there is text in the adjacent E-column cell (in Sheet2), and highlights if there is text.
try:
=REGEXMATCH(B2&"", "^"&TEXTJOIN("$|^", 1,
FILTER(INDIRECT("Sheet2!A2:A"), INDIRECT("Sheet2!E2:E")<>""))&"$")

Highlight duplicates when part of the cell matches in Google Sheets

I have searched as much as I can, and I have found solutions for similar problems, but I haven't been able to find a solution to my exact problem.
Issue: I would like to highlight the row when one cell in column A of that row is an exact match for another cell in that column, AND part of another cell in column B of that row is a match for part of another cell in that column, in Google Sheets. I would like to use conditional formatting, and only highlight the second occurence and on.
For example, is this "sheet":
A B C
1|John Smith|john#test.com|Test Co.
2|Jane Doe |jane#x.com |X Company
3|John Smith|j.s#test.com |Test Inc.
4|John Smith|jsm#test.com |Test Incorporated
I would like row 3 and row 4 to highlight, because column A3 is a duplicate of A1, and everything in B3 after # matches everything in B1 after #, and the same is true of row 4. Also, only rows 3 and 4 should highlight; not row 1, since it is the first instance. I understand regexes, and I've found how to highlight a row if one cell in column A and one cell in column B is an exact match with other cells is their respective columns, but I haven't figured out how to combine the two where I can search for one cell that is an exact match with another cell in that column AND for one cell that is a partial match with another cell in that particular column. Here is a link to a test sheet that contains the sample info from above. https://docs.google.com/spreadsheets/d/1neZd213C1ssY7bPeBfu2xI3WPCmt-oKkfbdrXrid9I8/edit?usp=sharing
use:
=INDEX(COUNTIFS($A:$A&REGEXEXTRACT($B:$B, "#.+"), $A1&REGEXEXTRACT($B1, "#.+"),
ROW($A:$A), "<="&ROW($A1))>1)*(A:A<>"")
Try the following custom formula applied to A1:C:
=index((countif($A$1:$A1,$A1)>1)*
(countif(regexextract($B$1:$B1,"#(.*)"),
regexextract($B1,"#(.*)"))>1))

Use Conditional Formatting in Google Sheets to highlight cell

Problem
I want to be able to highlight a cell in google sheets if a cell on the same row is TRUE and the value does not exist in a named range (or a sheet).
e.g.
Based on the scenario below in sheet1, if column a is TRUE, and the value in column b does not match anything in sheet2, highlight the cell red.
sheet1
column a column b
TRUE value1
FALSE value2
sheet2
column a
value2
I would like to do this in google sheets using conditional formatting custom formulas and named ranges (if required).
Edit
I have tried this with my sheet but cant manage it... I have copied my sheet example below! Are you able to work it with this?
sheet1
sheet2
Edit 2
Rather than just matching whats in Cell D I would like to only match the values of the string that is separated by commas and only search if the letters "tf" are in the string.
if column a is TRUE, and the value in column b does not match anything in sheet2, highlight the cell red
try:
=(A1=TRUE)*(NOT(REGEXMATCH(B1&"", ""&TEXTJOIN("|", 1, INDIRECT("Sheet2!A:A")))))

VLOOKUP. I have read and followed the directions for VLOOKUP, but I cannot get it to work.

I have read the other questions regarding Vlookup. I have my formula, but it is not working. I have a column of Zip-Codes in column e. I want to look for a matching zip-code in column m and then replace it with the county in column n. Please can you help me? Here is the formula:
=VLOOKUP(E2:E7807,M2:N962,2,false).
I have also tried using just 1 cell (E2) at the beginning of the formula instead of a range (E2:E7807).
Try below in the first cell.
=VLOOKUP(E2,$M$2:$N$962,2,false)
and copy and paste this cell in all required range of cells.