Rustboro City (1)

As you head inside, you'll encounter your friend. After the scene, head inside the PokeMart and talk to the guy in glasses to receive the TM54 False Swipe. This is a useful move in catching Pokémon as it ensures that there is at least 1HP left in the Pokémon that you are attacking. This is similar to the distribution Shiny Beldum's Hold Back move.

Leave the Pokemart and enter the Pokemon Center to the north. Heal up your Pokemon. The guy to the right in front of the map will tell you how you look like. He refers to your public profile in PSS. Selecting "No" and choosing one of the options will change your public profile. You can manually do this by accessing PSS in your PlayNav.

Next, enter the house to the left of the Pokemon Center. Talk to the man in the middle to receive HM01 Cut. You won't be able to use it yet outside the battle until you get the Stone Badge.

Exit the house and enter the large building north of it. Head upstairs and talk to the guy standing in the middle to receive a Float Stone. Head to the right and talk to the kid there to receive a Premier Ball.

From there, head to the middle right. You'll find the Pokemon Trainer's School there. Talk to the man near the entrance to learn more about Hoenn's Gym Badges. Next, talk to the teacher up front to get a Quick Claw.

The kid inside the house to the right of the Gym will trade his Makuhita for your Slakoth (You can capture one in Petalburg Woods) When ready, prepare your best Pokemon to challenge the Gym.