When you enter the city, as always, first use the Pokémon Center and the Poké Mart (to the north) as needed The Mart sells exactly the same as Oldale’s. As you head north of the Center you’ll see your father - Norman, the Normal-type Gym Leader of Petalburg - sending off another losing Trainer.
He invites you to the Gym. Anyhow, as you and your father make some small talk, a timid Trainer will walk in, requesting a Pokémon. This Trainer is Wally, who will also become a rival of yours in a sense. Anyhow, Norman will hand Wally a Zigzagoon and a Poké Ball as Wally heads off onto Route 102, dragging you with him.
As you get into the grass, he introduces you to what you already know; Pokémon hide in the grass. As he walks around, he finds one, a male Ralts! (Yes, it will always be male.) He then proceeds to exhibit the proper techniques to use when catching a Pokémon: lowering its HP and then throwing a Pokéball.
After the successful capture, you and he head back to the Gym and Wally suddenly decides to fiddle with your PokéNav Plus giving it the PlayNav . The PlayNav function allows you to access the PSS, Super Training, and Pokémon-Amie apps, much akin to the same ones featured in Pokémon X/Y.
After this happy occasion, you’ll speak to your father again. Rather than challenge him now, you should head to Rustboro City, the typical first Gym for Hoenn Trainers, which is of the Rock type and not far away.
Norman promises you a battle, one day, but you’re too wet behind the ears for that at the moment. Well, then. On to Route 104 !