From the village, follow the path as it leads eastward. If you cut down the bushes arranged like an arrow, you can enter the secluded grove south of the blacksmith's shop and find Gulley hanging around there. On the screen just west of your house, the witch you saw before will fly by overhead again. Visit Ravio if you want, then go east another screen to reach a bridge. Cross the bridge and continue east another screen, and the tile path will lead into the ruins region to the north.
Follow the path through the arches while defeating the Octoroks along the way, and head up the stairs to the next screen. Ahead, you will find several pedestals: two with crystal switches atop them and two with Bow icons. You can not proceed here, but if you read the purple signs, Ravio has an item rental shop now, so head back to your house to investigate!
Back at your house, Ravio asks you what the icon atop those pedestals looked like. Pick the correct option (the third one) and he will give you the Bow, which you are renting. All you need to know for now is that you don't keep the Bow permanently; if you die, Ravio gets it back so you will need to rent it from him again. Once you step outside of the house, you will notice a new energy gauge. You have unlimited arrows but can only shoot them if there is energy in that gauge. It refills automatically after a few seconds, and you can find energy quickly in the bushes and such.
Anyway, return to the eastern ruins area where you found those pedestals. Stand on the center platform atop the steps and shoot arrows at the crystal switches, which causes the path ahead to open. If you drop off the east ledge into the narrow path, you can collect 20 Rupees, but be prepared to defeat the Armos Knights surrounding it.
When you are ready, head north from the gate you just unlocked. You will see a building in the lower area, but you can't do anything inside for now (you can come back after completing the Eastern Palace and use your painting merge ability along the moving platforms to find 100 Rupees in a chest). If you go northwest, you can go up some steps and defeat a series of Armos Knights to reach a chest containing 20 Rupees. Follow the upper path as it leads further to the east, going up the steps and defeating enemies as you proceed. Once you approach the Eastern Palace, you will meet up with Osfala at last. He refuses to leave and enters the palace himself, leaving you to give chase. Use the weather vane to save, then enter the palace.
NEXT: DUNGEON: Eastern Palace