Instructions
Travel to the Great Deku Tree and open the treasure chest on the second floor to get the Deku Seed bag, which allows you to store bullets for your Deku Slingshot.
Enter Dodpongo's Cavern to earn the Bomb Bag, which allows you to store throwable bombs manufactured by the Gorons.
Go to the Forest Temple and open the first large chest to obtain the Quiver, with which you can store up to 30 arrows.