Definition of here goes nothing in English English dictionary
Indicates a lack of confidence or certainty about the activity about to be tried
Well, I checked everything and I think it's wired up correctly, so I guess all that's left is to turn it on. Here goes nothing!.
I am ready to begin, but this will be a waste of time; this will not be anything great; this will probably fail. Used especially before beginning something that takes skill, luck or courage
Here goes nothing, said Bill at the beginning of the race.