An IgG test cannot confirm location.
The general e rule would be if you cannot recall a genital outbreak, then a HSV1 diagnosis will be oral. You will have no knowledge of a HSV1 infection from your youth, but you would almost certainly remember the time if you were infected genitally with HSV1.
If you've had cold sores since childhood, you have oral HSV1.
An IgG test is the best way to determine this.