You get it in the Fire Temple as an adult.
Use the Megaton hammer, he can do any sword move you can.
when he sticks his head out of a hole smash it with the megaton hammer
The easiest way is to keep hitting him with your Megaton Hammer until he dies.
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
In Ocarina of time, you will eventually reach the Water Temple. Dark Link will be the semi boss. A tip to defeating this foe would be to use the megaton hammer.
There is nobody named "Gerard" in Ocarina of Time. Though from the context, you probably mean Goron, and the secret treasure is the Megaton Hammer, which you get in the Fire Temple. You get it by defeating the first Flare Dancer in the dungeon, activating the switch in the next room, and getting to the treasure chest before the time limit runs out.
You never meet Zelda's father in Ocarina of Time.
Not nessasarily but a little spoiler. There is a time at the end of the game when the Master Sword isnt available, but the Megaton hammer can be used too.
The Legend of Zelda Ocarina of Time does not have a remake on DS but it does on 3DS.
If you are talking about Ocarina of time, you can always find walkthroughs. But for the last boss; you have to use your hammer.
OoT is abbreviated for Ocarina of Time. The fifth Zelda game is called The Legend of Zelda: Ocarina of Time. People call it Zelda OoT for short =).
There is no such thing as a shovel in Ocarina of Time.