To pass Hero's Cave you'll need the following items: Cane of Somaria, Roc's Feather, Bombs, Pegasus Seeds

Hero's Cave is located on the screen just before the Maku Tree of the Present, in the rightmost cave. Inside, go up and light the two pots to open the door. In the next room, use the Cane of Somaria to place a block on one button, and put a pot onto the other. A chest will appear with a small key inside. Go right through the locked door.

In this room, kill the Keese and smash the pots on the right side of the room. Go down the path there and push the blocks so you can get to the bottom of the screen. Go up to the other side of the chasm from the cracked block. Hold a bomb and throw at the right time so that you destroy the cracked block. Go around and push the block just up from where the block was down and then the statue onto the button. A chest with a small key will appear. Use the key on the locked door and go up.

Kill the tektites and go up to the bridge. Stand on the spot just before the leftmost point of the bridge and use the shooter facing the bottom left to hit the switch. Quickly dash across the closing bridge and then cross the newly formed bridge. Get the small key out of the chest. Push the block to the top left of the chest to the left and go left through the locked door.

In this room, use your shield to flip the beetles and kill them while dodging the Like Likes- then kill those. Now, use the shooter so that hits the four statues and a chest with a Gasha Seed will appear.

That was pointless...