You go to Pewter City and challenge Brock.
Brock.
If you have gone in order so far the 14th gym leader should be Sabrina who is in the saffron city gym.
he is Brock. hes in pewter city.
You can fight the Kanto Gym Leaders in any order, except Brock, Blaine, and Green/Blue.
The 14th gym leader is the 14th gym you challenge, and there really isn't an order. However, in chronological order, the 14th gym is the gym in Saffron City, with Sabrina as the gym leader.
the first gym leader is brock.
The names of the Gym Leaders in the Kanto region in Pokémon SoulSilver are Brock the Pewter City Gym Leader who specializes in Rock-types, Misty the Gym Leader of Cerulean City who specializes in Water-type, Lt. Surge an Electric-type specialist and the Vermilion City Gym Leader, Sabrina a Psychic-type specialist and the Saffron City Gym Leader, Erika a Grass-type specialist and the Celadon Gym Leader, Janine a Poison-type specialist and the Gym Leader of Fuchsia, Blaine the Fire-type Gym Leader of Cinnabar Island and Blue the Viridian City Gym Leader.
The next gym leader is Misty in Cerulean city
You head to Pewter City and battle Brock there gym leader! Then from there you head south to Virdian City. There gym leader won't be there so you keep on to Pallet Town. Then pass Cinnabar island and head to the seaform island and challenge the gym leader! Then after you defeat there gym leader talk to the Virdian Gym leader at Cinnabar island and then you go defeat him at his gym
The third gym leader is Whitney.
He is where he always is, at his gym in Pewter City
Brock the rock gym leader