First of all, you should try to get into the cold brake as soon as you get in. In fact, getting in is quite simple. All you have to do is walk to the top left. After entering that maze, there are many bridges, wall passages and so on, but there are no secret passages. Just go straight to the upper left after entering. Then go to the end and you will see a house with blue pictures. There was a cold brake sound. When you walk into that room, you will find a DOMO staff member. He will ask you for a paper crane, because he can't get out and is trapped in this maze. He won't go back until you give him a paper crane.
As for Yu Fulu, I don't think it is very useful, because there are blue squares, rat hammers, star eyes, afterwords of Sanqing, strange ancient jade, and a name I forgot.
It is best to equip Chen Jingchou with strange clothes, because the ending is different, and one of the two heroines will leave, depending on the heroine's goodwill. If Xiaoxue has a good impression, Xiaoxue will stay. If you don't know what a good impression is, you'd better equip Chen Jingchou. Then it won't be so difficult to fight monsters in the future. Because Langer's clothes have grown up completely, and the damage is more than 9000.
The palace is in the cold sound brake, close to the tree on the left side of the house. Just press the space bar to go there.