When I saw the thread title, I thought you were on about going the toilet.... And still looked
Hatching hens eggs is easy, I wouldnt worry about humidity too much unless your hatching expensive breeds.
Goose eggs can be got from quite a lot of farm stores, on the counter, intended for eating, these will usually hatch if their not too old.
When you hatch out the turkey poults, stick a hens egg or two(just to be safe) in there about 5 days after you set the turkey eggs and this should hatch first and show the slightly backward turkey poults how to find food and water.