you may not believe me but steven went to the shinno region
You can go on to defeat the Elite Four.
Go to the battle tower
go home get looker
After defeating the Elite Four and Champion. Get on it to go to Fight Area.
You can now go to mystery dungeon in Cerulean City and go look for Mewtwo!
Just press Continue. well you have to wait till all the guys tell you what they did to make the game and then go turn it off and back on.
You can use potions ,but I believe you mean if you can go to a Pokemon center,which is no.
go to Viridian City, go west, and challenge the Elite Four
Beat the elite four and go to steven's house plafidog city
once you beat the elite four, you go back the the lab and get the SS ticket. take the boat and you'll end up in vermillion
steven doesnt go anywhere u can chalenge him any time u want HOPE IT HELPED
he flys around kanto mostly around the entrance to the elite four