Mary, a transcription of the civil record on RootsIreland shows the couple married in the parish of Newcastle, Co. Limerick, on 29 Jan. 1918, in Newcastle West RC Church.William lived in Churchtown, Julia in Church St. He was a farmer, she was a servant. His father: James. Her father: John. Both were farmers. Witnesses: John Flynn, Maggie Fitzgibbon. You can see the civil record at irishgenealogy.ie.
There would also be a church record available.
With this info, you can search irishgenealogy.ie civil records AND rootsireland.ie baptismal records for a Wm. Lenihan, son of James, born about 1892. Ditto for Julia McCauliffe.