Final answer:
Magellan's first destination reached during his voyage was Guam, before heading to the Philippines and eventually completing the first global circumnavigation.
Step-by-step explanation:
During Ferdinand Magellan's voyage, the location he reached first was Guam. Magellan's expedition set out from Spain in 1519, crossing the Atlantic and navigating around South America through the passage that would later become known as the Strait of Magellan. After enduring the crossing of the Pacific Ocean, on March 6, 1521, the fleet reached Guam. This preceded their landfall in the Philippines and the eventual completion of the first circumnavigation around the globe by Magellan's fleet, which confirmed his achievements posthumously, as Magellan himself died in the Philippines.