you don't first you talk to blue at cinnabar. then you go to Viridian and battle him at the gym then you go battle red at mt. silver.
You battle them when youre done battle and beat your rival(silver) he'll say that he'll go to dragon den an you'll see just walk to him
You go to Mt. silver and battle Red.
when you get the silver wing you go to the 4 islands between Olivine City and Caniwood City and battle LUGIA.
go to the beach in olivine
after getting all 16 badges go talk to prof. Oak then go to mt. Silver
he's at the top of mt silver. talk to him he'll go "..." then he'll battle you.
you go up the stairs in the Pokemon center and the lady in the right will let you battle
after having all your battles with your rival SILVER in the game go to DRAGON DEN then talk to him. Then LANCE and CLAIR well appear then you and SILVER well battle them (in a double battle).
go to mount silver and walk until you reach a trainer. he is red. he will say...... then battle you.
he will go but then he will be on mt-silver every day for you to battle but his pokemons level will not increase
Beat the Pokemon league and then go to olivine city and go into the building that was previously under construction. You will then be escorted the the battle frontier