Fishing is a skill which all players can learn, after defeating Misty. An Old Rod can be purchased for $5,000
at a Fisherman's house in Vermilion City. While fishing, you will unlock new areas and access to new rods.
Lv 1: Old Rod
Lvl 15: Safari Zone
Lvl 25: Cerulean Cave
Lvl 30: Toto Cave
Lvl 40: Dragons Den
Lvl 80: Ancient Dungeons
A bar will show up. What to do?
There will be a "Hook Icon" that's going to move left and right. You will need to press Space Bar to stop the hook. If the hook lands in the yellow box, you'll hook a Pokemon(see image 1). If the hook lands at the tiny green box, you'll *perfectly* hook the pokemon which will give you more Fishing XP(see image 2).
What's Fishing XP?
Fishing XP is experience to level up your fishing level to unlock higher level Fishing Rods, and unlocks fishing in new areas.