Explore the town and get the various items available to you at this time. The most important things to get are the Hylian Shield from the graveyard, the second bottle from the girl who lost her cuccos, and the Song of the Sun in the graveyard. Once you've got what you need, talk to the guard at the North part of town and show him Zelda's letter. Don't listen to him about buying a shield...you can find one for free in the graveyard. He'll talk about wanting a mask which you can now go and get from the Happy Mask Shop in the market. If you wish you can now do most of Young Link's Trading Sequence (See the Howto section or click here). Go past the guard and head up Death Mountain until you find Goron City.