need help with a macro to make certain text within the entire sheet BOLD

Try this:

Private Sub Worksheet_Activate()
    Dim wsBL As Worksheet
    Dim LastPORow As Double
    Dim LastBLRow As Double
    Dim PORowCtr As Double
    Dim BLRowCtr As Double
    
    Set wsBL = ActiveWorkbook.Sheets("BoldList")
    ActiveWorkbook.RefreshAll
    
    LastPORow = Cells(Rows.Count, "F").End(xlUp).Row
    LastBLRow = wsBL.Cells(Rows.Count, "A").End(xlUp).Row
    
    Columns("F:F").Font.FontStyle = "Regular"
    
    For PORowCtr = 6 To LastPORow
        For BLRowCtr = 2 To LastBLRow
        With wsBL
            If Cells(PORowCtr, "F") = .Cells(BLRowCtr, "A") Then
            Cells(PORowCtr, "F").Font.FontStyle = "Bold"
	Cells(PORowCtr, "F").Font.Color = 255	
            End If
        End With
        Next BLRowCtr
    Next PORowCtr
    
End Sub

The RGB number for RED is 255. See:
http://access-excel.tips/excel-vba-color-code-list/