If you mean in the Wind Waker, then he is at the back of outset island, you have to blow up a cracked wall to get in,
but if you mean in the ocarina of time, then he is in the lake area behind the zora king, you have to give the king rutos note that you get in lake hylia to make you let him pass
Inside lord jabu jabu's belly.
I am not sure this is what you meant but to get into Jabu-Jabu you take a fish and put it right in front of his mouth
Barinade is the boss of Inside Jabu-Jabu's Belly, the third dungeon in The Legend of Zelda: Ocarina of Time. This parasitic organism is revealed to be the cause of Lord Jabu-Jabu's gastrointestinal distress. It appears to have a symbiotic relationship of some sort with Bari.
Use you Level 2 Switch Hook
You don't kill Jabu Jabu yourself. However, after seven years pass and you become Adult Link, where Jabu Jabu is in Zora's Fountain is replaced by ice. There's no explanation for his absence, although it's possible that Ganondorf may have killed him.
You get the boomerang while you're a child in Lord Jabu-Jabu's stomach. It is obtained after beating the mini-boss.
Inside of Jabu's Belly
You either buy one or you scoop one up in the shallow part of zora's domain.
Use your boomerang and make it around the wall and hit the swicth
As adult Link, head to the shrine where Jabu-Jabu was as a kid, hop the ice to the cavern, and complete it to recive the iron boots.
The compass is found many times throughout the game because there is one in each dungeon. The boomerang is found in Jabu Jabu's Belly
The Zora's Sapphire, you mean? To get it, complete the Jabu Jabu's Belly dungeon, which requires the use of the Boomerang and shooting your slingshot at cow heads.