Sharon, The Army Air Force later became the Air Force. If your father was killed in the service his wife would have received notification. There would be documents showing where he is buried.The 5th Air Force and the 13th Air Force were in the Pacific. There may have been others but these are the two I am working on. Do any of the photos show a shoulder patch? That would show which one.
On the documents your grandmother should have would give his service number. With that you can write for his records.
I think you are going to have to have a bit more to go on. But definitely ask if your grandmother left the documents with your mother or another family member. If you know where he is buried there is information there as well.
I will be glad to help you and I am sure there are others who will respond and who are much better with all of this. Regards Mickey WE MUST NEVER FORGET