In Dragon Ball DAIMA Episode 4, “Chatty,” Goku changes his plan. While he initially intended to head straight to the First Demon World to fight and defeat Gomah, he instead chooses to collect the Demon Realm’s Dragon Balls, so that he can return himself and his friends to adulthood before he fights Gomah. Despite how it seemed prior to the reveal that Glorio works for Arinsu, Goku didn’t make this choice on his own.
Arinsu wanted the Dragon Ball for herself and, with Glorio having spent enough time around Goku to know how to sway him, he told him about the Tamagami, emphasizing how strong they are. Glorio may have been directly taught how to manipulate others by Arinsu, as he’s able to take advantage of Goku’s love for fighting powerful opponents, and make him think that seeking out the Dragon Balls was his idea.
Obtaining the Demon Realm’s Dragon Balls is the main purpose of Arinsu’s back-up plan. Even though it would be beneficial for her if Goku and Gomah were to destroy each other, Arinsu’s main use for Goku is to travel across the three Demon Worlds, defeat all the Tamagamis, and claim all three Dragon Balls. Once he’s accomplished this, Glorio will be in position to betray him and steal the balls for her. If Arinsu’s main plan fails to net her dominion over the Demon Realm, she’ll be able to wish for the position of Supreme Queen using the Dragon Balls.