Instructions
Defeat the Elite Four and the Champion. Talk to Professor Elm to get the S.S. Ticket. Fly to Olivine City and board the S.S. Aqua at the docks.
Find the captain̵7;s daughter in a game of hide-and-seek, and she will return to the captain̵7;s cabin. Talk to the sailor at the ship̵7;s entrance, and he will announce that the ship has arrived in Vermilion City. Exit the ship.
Head north to Saffron City and then west to Celadon City. Exit Celadon City to the west, and then head south down Cycling Road.
Head east to reach Fuchsia City. This unlocks the ̶0;Migrate̶1; option on the game̵7;s startup menu, allowing you to enter the Pal Park building at the north end of Fuchsia.