Gina, it wounds like you are in a beautiful place!
I am more of a flower pot gardener, purslane lover and artist (see the Forum here on ATP called Garden Art) so am no help at all with soil and so forth. Hopefully someone else will show up. This forum isn't very active.
Now if you have any questions about purslane, I can help you.
But if you grow it, the chickens will love it too so keep it in hanging baskets.