MCPE seed which contains a very interesting island. The size of it a lot more than that to survive. To Minecraft PE players on large Islands can hold for a long time. The main purpose of this island is a metered space, which for some is the highlight. On a normal ground, you can do whatever you want, and when there is no restrictions, the game becomes boring.
On this, surviving on the island, you will always have in mind that resources are limited, and space on which to build something is also limited. You have to think how to use resources and minimize construction.
Suggest You use a seed, in which generation, Your spawn will be on the big island with trees and animals. Seed is for Minecraft PE 0.16.0+
After generating, You will immediately be in the right place:
This is a big island in the middle of the ocean. It here will be the animals and trees: