A James Johnston Young was commissioned from a cadet into the Royal Dublin Fusiliers dated 2 July 1918 (London Gazette). He had been 19/894 in the Royal Irish Rifles. He was posted to 3rd Battalion RDF. (Findmypast). 19/ prefix suggests 19 Battalion which did not service overseas and nor did 3rd Bn RDF.
A man of the same name had been commissioned also from an officer cadet unit into the Scottish Rifles dated April 1917. Went on to be promoted Lt in Nov 1918 (London Gazette)
As jim1 has said, no medal or further records found.
MaxD