Hi Barry,
Goslings should stand up within hours of hatching (a little wobbly at first).
They need duck / goose crumbs - check you are not giving them chick crumbs as most of these contain a coccidiostat (drug) and they will be eating more than the chicks would eat and get the wrong dose.. this can effect the growth of their joints which could be causing them to struggle standing.
When there is fresh grass available, then after a week or so, they usually leave the crubs and go for the grass. They will usually do very well on just grass alone.
I would get them outside as soon as you can but remember if they don't have a mother, they will happily get wet when it rains and get cold so you need to play mother a bit until they are fully feathered.
Tim