Fire Temple.
Yes in ocarina of time you can skip the fire temple. that's what my friend told me. how it helped :)
You should try a walkthrough
I would suggest looking up a walkthrough or watching youtube.
Bomb it, it will break.
You get it in the Fire Temple as an adult.
Go to zelda.com go to ocarina of time on the game list and go to official site and go to master quest version and then go to dungeons then finally go to fire temple it should have a perfect walkthrough for it hope it helped :)
If you mean Temple, then all 5 temples in order are: Forest Temple, Fire Temple, Water Temple, Shadow Temple, and Spirit Temple.
Free all the Gorons, get the Megaton Hammer, knock down the block and beat the boss (Volvagia). For a more detailed description, follow this link: http://www.zeldadungeon.net/Zelda05-ocarina-of-time-walkthrough-08.php#8_4
If by that you mean the Fire Medallion in Ocarina of Time, completing the Fire Temple will get you it.
Collect keys, get a super strong hammer, and kill a fire dragon.
In The Legend of Zelda: Ocarina of Time for Nintendo 64, the Sage of Fire is the Goron leader, Darunia.