not able to create a functioning VLOOKUP, MATCH, INDEX formula

well not seeing your data this could in theory work.
=VLOOKUP(A3&" 01",Sheet2!$A$3:$B$12,2,FALSE)
so for example if you have location 123456 in A3 and 123456 01 in sheet2 A3 then it will return what is in column B.
Adjust per your actual data.
for a better answer you probably ought to post a sample sheet.

There are several possibilities. One is that the data types (numeric / text) are not of the same type. Appearances can be deceptive.

Without a representative workbook upload it is difficult to say.

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so for example if you have location 123456 in A3 and 123456 01 in sheet2 A3 then it will return what is in column B.

Your first post says you have unique numbers in col A of sheet1 and unique location numbers with 01 in col A of sheet2.
So what I created was a unique number, 123456 in A3 of sheet1 and 123456 01 in A3 of sheet2.
then used that vlookup.
the formula is saying take the value in A3 (of sheet1) and add to it the text space 01 " 01" and find that value in column A of sheet2 and return the value right next to it.
This is simply written based on what you wrote in post 1.
it can be added to in case it errors out for a " 02" like so...
=IFERROR(VLOOKUP(A3&" 01",Sheet2!$A$3:$B$12,2,FALSE),VLOOKUP(A3&" 02",Sheet2!$A$3:$B$12,2,FALSE))
But either way, without a sample sheet we're just guessing.