FiRsT you finish the gym on cinnabar island .after you have finished it and are coming out you will meet bill.he will ask you to go to an island say yea.you will reach one island
One Island.
go to one island and talk to celio
Uh u kinda go to one island go to my ember where the cave is
go to the lab on cinnabar island and give it to one of the scientists
go to cinnabar island and once you beat the Pokemon mansion Bill will come out and offer you to go with him to first island.
he isn't in the one island
one island
beat the elite four then go back to island one and talk to Celio in the Pokemon Center
you need to go to one island and go in the Pokemon net center and talk to celio
go to one island. on the pier, surf on the left side of it. go down to the beach
do the errand for bill on one island.
go to 7 island