Begin by heading to any of the pigs you see nearby (there are three in all). Crouch and crawl to one by using the R button and the Control Stick.
Once near a pig, release R and press A to pick up the pig. Next, head to the part of the island that has your grandmother’s house and go up to the top of the hill. You should see a fenced-in area.
Next, head to your grandmother’s house. Look to the left of the ramp outside. If you look carefully, you should see something like a crawlspace going under the porch. Press and hold R to crawl under there, then follow the path.
You’ll soon end up in a room underneath the house. A chest is here - with an Orange Rupee in it. That is worth 100 Rupees! Exit the crawlspace.
Okay, one last thing, then back to the storyline. Look out towards the ocean. You should see a small ship there. Swim out to it and enter the ship. Inside, buy a Bait Bag. Buy 6 ~ 8 All-Purpose Baits and fill the remaining slots with Hyoi Pears. These will be very useful - even needed - later in the game.
Finally, go back to your grandmother’s house and enter. Climb the nearby ladder to find your grandmother waiting for with some green clothes. See, Link has now become of age to wear these clothes (see Section I) like the hero once did.
She also mentions the fact that Orca is the only person on the island to practice in the way of the sword nowadays - remember that for later. After Link reluctantly gets into the clothes, Grandma tells him about her plans for his birthday and sends him to find Aryll.
You should try it out now (you will be forced to anyways!) and zoom in on the postbox. Near the postbox is a bird-man (the postman), or Rito. Suddenly, he freaks out and looks far above. Move the view upwards. You’ll see a massive bird holding a girl and being shot at from a ship.
One cannonball strikes the bird, causing it to let go of the girl and fall into the forest on the island. Aryll states the obvious - the girl needs help, but it is too dangerous to enter the forest without being able to protect yourself.
You may remember from earlier that Orca is the only person on the island to practice in the art of the sword. Go to the two-story building near the shore. If you wish, enter the second-floor for some useful advice if you’re new to this game. Enter the lower floor when you’re done.
Speak to Orca. He realizes from Link’s expression that something must be wrong. He offers to train you in the ways of the sword. Accept to begin the "match". First is the horizontal slice. Press B only.
Do it twice to go to the parry (L-target with unsheathed sword, press A when button shape changes). Your final lesson will be the jump slice (L-target, press A). Repeat to finish your training. You will also recieve the Hero’s Sword! Now, exit the building.
Go back across the bridge. Follow the dirt path up a hill until you come a few trees that are blocking your way. Press B to cut them down. Climb up the hill. You’ll soon get to a bridge. Cross it, jumping over the gap as you go, and then enter the forest.