Now there are a bunch of guards around. It's OK if they see Link, but if they see Zelda, you'll get in trouble. You can control Zelda by touching the pink swirling icon at her feet and then drawing an arrow of the path that you want her to take. You can tap the Switch icon to see where Zelda is, and then you can tap the Call icon to have Link call her over to his location.
You can see the positions of all of the guards in the top screen. Each guard has an orange cone in front of him on the map that shows the area that he can see. Keep Zelda away from the orange zone at all times. And be sure to watch the movements of the guards to see when it's safe to make Zelda go past.
You need to exit through the far-right exit on the map. It's not too hard to get past the guards to reach that spot. You might try making Zelda go to the exit, then have Link run over to her, then press the Switch button and then Call to get Zelda to follow you again, then run out of the door.
Outside, Zelda points out that there is a soldier who is just standing there. Zelda asks you to create a distraction and then draw a path for her to get past unnoticed.
First, call Zelda if she isn't already following you, then jump down and hide behind the top bush. Draw a short path for Zelda to stand to the left of the long bush, but not too close to the guard. Then have Link walk to the right of the guard and talk to him. While the guard is distracted, make Zelda walk between the two small bushes in front of that guard.
Next, there is another guard who is just standing there. Have Link stand behind him on the left side and talk to him while Zelda walks below the long bush.
Next, there is another stationary guard up ahead. However, he won't turn around if Link talks to him. Instead, if Link throws a rock, the guard will go investigate the noise. First, position Zelda at the left side of the bush that she is hiding behind. Then, there are rocks above the guard, so throw a rock to the left to make the guard run that way, and have Zelda run to the exit while he's away.
Soon you'll see a bunch of automatic scenes. You'll wake up in Hyrule Castle. Talk to the Teacher. Once you talk to him, leave the room and head toward the central staircase. Zelda's spirit will be trying in vain to talk to the guards. Follow her up the central stairs, then head toward the throne. Follow Zelda into the door on the right. You have to tap the door to open it. Next, go up the stairs to Zelda's room.
Zelda gives you the Spirit Flute, and she will go along with you. She wants to try going to the Tower of Spirits again. As you try to leave, Zelda will realize that you can't get there by train anymore, so Zelda tells you to check out the door in the back of the castle to see if you can find the secret path to the Tower of Spirits there.
Go out of the room and tap the door below you to open it, and go through. In the throne room, use the door on the left. Next, go straight up and use the stairs.
There's only one door here, as well as a guard. But go past the guard because there's a treasure chest containing 20 rupees. Talk to the guard and he'll say that because of the enemies beyond the door, you need a sword. Go back up the stairs, then head to the bottom-left corner of this room to find another 20 rupee chest. Then go back up to the columns and use the exit to the left of those columns. There's a chest that contains a random bit of treasure.
Now go back inside and go through the big door to the right of the columns. You'll be back in the throne room. Take the south exit. Go a little bit south to where the path splits, and go to the right, then up. Go through the door here and talk to the guy on the left. You'll get the Recruit's Sword and you will have to learn swordsmanship from the Guard Captain before he lets you leave. Just do what he says, and ask him if you need help. To do the targeted attack, just tap on the soldier. To do the side slash, draw a line across the thing you're attacking. To do a spin attack, draw a circle around Link.
You should have a fair amount of rupees by now, so if you want to, you can cut grass until you have 80 rupees, then go into town and buy the shield.
When you're ready, go back to that door with the guy who told you to get a sword, and then go through the door.