After you make your way through the northern part of Route 210, you arrive in Celestic Town.
Get an Item
In the Pokémon Center, talk to the person near the escalator. If you have good friendship with the lead pokémon in your party, the person will give you an item.
Get Wise Glasses
Go into the northwest house and talk to the person wearing dark glasses to get a pair of Wise Glasses.
You can also buy items in this house.
Get a Pokétch App
In the house west from the Pokémon Center, talk to the Black Belt to get the Analog Watch Pokétch App.
When you go west of the Pokémon Center, the person tells you about the "spaceman" blocking the entrance to the ruins. Go north down the stairs and talk to the Team Galactic Grunt. Say Yes if you are ready to battle.
Team Galactic Grunt
The grunt has a level 25 Beautifly and a level 27 Croagunk. You get 1296 Pokédollars for winning.
Go to the Ruins
Afterward, go north and enter the ruins. Go to the north wall inside the ruins and check on the painting in the back. You will get some TM95s, which teach Surf. You will need to get the badge from Hearthome Gym before you can use Surf outside of battle.
When you leave the ruins, Cyrus will speak to you.
Go to Hearthome Gym
Use the Town Map to fly to Hearthome City, where you can challenge the Hearthome Gym.