Talk to Blue on Cinnabar Island.
You defeat them by training against wild Pokemon.
I would suggest using a Fire type for Pryce's Piloswine, and an Electric for his Dewgong and Seel.
you defeat a gym leader
You must defeat Team Rocket.
you must defeat red and he will give it to you
Defeat the Mahagony Gym.
to battle Blue in Pokemon Heartgold you must defeat the 7th gym leader, then find him on cinnabar island. Talk to him, then he will go back to his gym for you to fight
you go back to olivine
Use a steel type pokemon, they areresistent to dragon types.
the first seven badges are with the gym leaders that you have to defeat
After you defeat her, you will automatically register her in the Pokegear.
train them a lot to around 20