Skipping rows when false (copying cells from one sheet to another)

Hope the bright excel minds can help me out.

I saw another post that was doing exactly what I wanted to do, but I don't know the formula well enough to transfer it to my own spreadsheet.

I have: Sheet 1 where I enter information (cell text) that I want to automatically transfer to Sheet 2. It is Columns A and C (sheet 1) that I want copied to Sheet 2 based on a true result in column B.

Issue I have is that using my IF statement =IF('Requisition #''s'!B2:B25="21300-21301",'Requisition #''s'!A2,"") I get the blank rows (for example, rows 1 and 3 are true so info is copied, row 2 is false so I get a blank row that if I delete I get a row error)

The formula that worked for another user follows, but is a bit complex for me to figure our how to transfer it to my needs.

They had: a Helper row (they had Sheet 2, but mine would be on Sheet 1) =A1&"_"&COUNTIF(A$1:A1,A1)

Then on their Sheet 1 (my Sheet 2): =IFERROR(INDEX(Sheet2!$B:$B,MATCH(OFFSET(K2,-(MOD(ROW()-2,12)+1)+1,-(MOD(COLUMN()-1,3)),1,1)&"_"&MOD(ROW()-2,12)+1,Sheet2!$D:$D,0)),"")

Advice appreciated! Thanks.

Trish