Question: what to do after you beat soul silver?
Answer: Well once you have beat Red you can now get the Hoenn starters in Silph Co. in Saffron City. ... 
- You can get Kanto Starters. ... 
Go get all the phone numbers, go capture all legendaries, go to battle frontier, go to pokeathlon, go to safari zone, go complete your pokedex, DO WHAT YOU WANT!!!!!!