just walk out
The first gym is in pewter city.
The 5th gym is the Fuchia city gym Gym leader Koga
his gym
You have to beat the 2nd gym.
in the museum
you got to beat all the Pokemon gym leaders in kanto other then blue,then talk to him
In Pokemon Blue, the fourth gym a player may battle is in Celadon City. One of the player's Pokemon must know the HM Cut in order to access the gym which is a Grass-type gym.
Blue is the 8th kanto gym leder.
i think top of Pokemon mansion
Giovanni, he has rock type Pokemon
Dewford town.
2nd.