IMHO difficult to find a first one man foiling vehicle with one or two ... or other foil constructions,
as there has been foils from the beginning of the last century so more than 100 years of history.
Wikipedia (Ing. Enrico Forlanini, 1910)
But the following could be the first kite powered foil ever:
(sorry for quality will digitise the VHS video some day)
Video has copyright from 1996 showing kiteski system and also a guy riding an early airchair foil with it.
So you could say the first form of riding a kite foil was sitting and if you want one of the first forms of kiting was foiling ...