Do you know for sure that there was a licence? Does it say that on the marriage entry?
I had a quick look on the Norfolk Record Office catalogue, and although one or two Girdlestone names came up with marriage licences, there was none for a William.
familysearch.org are also supposed to have Norfolk marriage bonds and licences, but again nothing comes up in a search.
https://www.familysearch.org/search/collection/1824690If William was over 21 years old, it's unlikely to give any information about his parents, but you never know.
Have you seen the entry on findagrave? (It may be your entry for all I know).
He died March 1823 at Holt.
https://www.findagrave.com/memorial/201062359/william_girdlestoneAlthough it doesn't give his parents, it does list his wife and children.
There is no photo but I would think it worthwhile to see if you can get one.
There is a facility on the site to 'request a photo', and/or you could put out a plea here on Rootschat to see if anyone lives nearby and could go and take a photo.
There is some interesting information about his wife Ann Browne Bolders - which you may or may not already have.
She was evidently born 13.3.1747 in Steinheim, Germany.
There are also some 7 children listed on the entry on findagrave.
I noticed there was a son
Elisha born in Feb 1784, and died in May 1784.
Is this a family name? One would have thought so, it's quite uncommon.
Have you looked for wills for the family. This would always be my first thought as you can often find relationships this way.
There are some 38 entries indexed for Girdlestone wills on findmypast.
I don't have a sub so can't look at them, but it would be worthwhile doing so.
There is a will of
Elisha Girdlestone, Gentleman of Holt, 1786 at the PCC on the National Archives site - free to download.
https://discovery.nationalarchives.gov.uk/results/r?_col=200&_cr1=PROB+11&_hb=tna&_q=%22Elisha+girdlestone%22Unfortunately it just says 'my sons', and names one of them - another Elisha.
Surely there must be some relationship here.