Beat Giovanni at viridian city's gym.
the boulder badge from brock
Fuschia city.
In Vermilion city.
fuschia.
fap
Beat team rocket at mt moon, Pokemon tower, game corner and silph co and get the 7th badge now you can fight the last gym leader.
Head to Cinnibar Island for your next badge.
vermillon city
The last gym leader is the boss rocket to get him to the gym beat team rocket at: Mt moon, Game corner, Pokemon tower, Silph co. After you do this get the 7th badge if you haven't then you can get the last badge in viridian city.
Vermilion city.
In cerulean cities gym you must beat the leader misty to get the cascade badge.
Fight Misty laduh