you go to the radio tower in goldenrod city and fight off team rocket good luck!
You can but only after defeating the red gyrados.you find him in the poke mart thing in mahogany town...
any gym that you havn't done. there is no specific order.
You can vs Pryce in Mahogany Town(east of Ecruteak City through Mount Mortar) after capturing/defeating the Red Gyarados and defeating Team Rocket in their base. He has a lv 30 Seel (water), lv 32 Dewgong (ice/water) and a lv 34 Piloswine (ground/ice).
Mahogany town
it is in between Mahogany town and Ekruteak city
on the route between mahogany town and blackthorn city
gem leader blue
After you beat pryce in mahogany town
The seventh gym is located in Mahogany Town, which is east of Ecruteak. You first need to clear the disturbances in the Lake of Rage, and then do the quest with Lance. Then you can enter and battle the gym leader, who uses the Ice type.
After defeating the champion in heartgold and going through diglett's cave
ecruteak city
In her Gym