How do you get to Fuchsia City

Talk to the Snorlax which blocks your way to Route 12 or Cycling Road; it will ask you if you want to use the PokeFlute. You get the PokeFlute from the old man in the Lavender Tower in Lavender Town. After catching/battling the Snorlax, go through Cycling Road/Route 12, 13, 14, and 15 until you reach Fuchsia City.