When first entering, you and your rival will talk to Prof.Ivan. He will then ask you to get a package for him in Mainland Station Cave.
Before that he will give you and your rival pokemon to protect yourselves. Choices are Dratini,Bagon and Gible. After choosing one, your rival will then choose and challange you.
After battling go outside.
After Obtaining the Package
Go inside and Talk to Prof.Ivan and while talking, your rival arrives finishing what Prof.Ivan asked him. After giving him the package. Your Journey begins as he give you and your rival pokedex and pokeballs.
Items
Items
Pokedex
Given by the professor after delivering the package
PokeBalls
Given by the professor after delivering the package