What do you do after you get the soul badge?

Answer 1

You're supposed to head down to the beach south of Fuchsia City, and use Surf. Continue down the waterway, and you'll eventually find an island. These (this?) are the Seafoam Islands. You'll need plenty of health restorers, and possibly a lot of Ultra Balls. This is where Articuno can be found. After you get out of there, continue west until you find another piece of land. This is Cinnebar Island. This is where you will have your next gym battle. But you'll need to find the key first~

Look in the mansion. And remember, have fun with it!