Answer to Question 1
Indigenous settlers are a bit of an oxymoron, but the earliest settlers that would have been the most local to Hawai'i would be settlers from Polynesia.
Answer to Question 2
Trade winds are persistent winds that blow from east to west in tropical oceans throughout the world. Trade winds are driven by warm, moist air rising at the equator and travelling at high elevations before sinking in the subtropics at about 25 degrees north and south of the equator. The air sinks in the subtropical region and flows along the surface of the Earth back toward the equator. This produces a steady wind that is then deflected by the Coriolis effect from east to west. When this water-laden air, moving over the ocean encounters the volcanoes of Hawai'i, it is forced to rise again, depositing copious amounts of rainfall along the east and north coasts of the island.