i have grown them in banana circles.
a pit in the middle dug out and filled with rotting wood, leaves, grass, coffee grounds....
it will hold water even in hot sun, just put as much woody mulch on top as possible.
the soil organisms and worms go wild, it stays moist and fertile.
ive been using logs to provide barriers for raised beds too, that also works well.
as far as the male-female thing...
my understanding is that almost all papaya sold are grown from seed which is
cultivated, over generations, to produce mainly hermaphrodites.
usually %66 or more herm, with %33 female and almost no males.