The English name of the original Pokémon anime’s main protagonist is Ash Ketchum.
Ash is the English localization of Satoshi, the protagonist’s Japanese name. He begins his journey from Pallet Town and travels through multiple Pokémon regions while pursuing his goal of becoming a Pokémon Master.
His first partner Pokémon is Pikachu, which he receives from Professor Oak after arriving late to collect one of the standard starter Pokémon. Their relationship became the central partnership of the original animated series and helped establish Pikachu as Pokémon’s global mascot.
Gary Oak is Ash’s recurring rival, not his name. Brock and Tracey Sketchit are traveling companions who join him during different parts of the series. Ash remained the anime’s central character for many years before the series introduced new protagonists, Liko and Roy, in Pokémon Horizons.