to beat the cerulean city gym leader, first heal up your Pokemon and buy about 3 super potions and 3 potions. if you chose bulbasaur, you have no problem just use grass attacks. if you chose charmander, hard luck staryu and starmi are water Pokemon. if you chose squirtle (he should have evolved to wartortle),you need the super and normal potions. it worked for me.
The answer is pretty obvious although you could have chose bulbasaur as your begginer, if not you could just take the harder route by training your Pokemon more. I myself trained my charmander until he was Lv. 30, before i took on misty.
You can use 4 level 25 Pikachus using electro ball on the outside and 1 Graveler using rock blast in the middle.
In cerulean cities gym you must beat the leader misty to get the cascade badge.
beat erika, fourth (celadon) gym leader, who uses grass Pokemon
You either go and beat the 8th gym leader Geovanni in Viridian or go to with bill to the island and train plus do him some favours
you beat the elite four and then go to the cerulean city cave. get to the end then prepare for the fight of your life. ps bring repeals and ultra ballt
its in the cave beside cerulean town.But you must beat elite 4 and Gary first to gain access to that cave.Before you beat the elite 4 a man will be blocking the cave. You must have surf to reach there.Hope that helps
In cerulean cities gym you must beat the leader misty to get the cascade badge.
You have to beat the Elite Four once.
You have to beat the elite four and complete your pokedex.
You have to beat the Pokemon league 12 times then you can find it at Cerulean Cave.
You have to beat the game then you will be able to go in I bealeave mewtwo is in there
beat the gym leader
you have to beat the pokemon league then help the first chick stop team rocket on her home island
Beat the elite 4 and champion, then the man will stand aside and let you enter.
you have to beat the elite four, and get the national dex. then go to cerulean city, go past the nugget bridge, and surf on the water. there is a cave,and its cerulean cave
maby you have a old version of Pokémon LeafGreen and when it came out , the Cerulean Cave wasn't finished.
beat the elite four and then you can go to the kanto region and you have to beat Brock, then get though Mount Moon to get to Cerulean city
You work on your pokedex if you've not filled it yet, when you do that fill national dex and then into Cerulean cave you go! Good Luck