what do the boys discover about their surrounding?

Most of what they know happens in the early chapters of the novel. The island is an Eden-like setting. They go on a quick excursion to make sure it is an island. They know there is fruit, wild pigs and fresh water. There is a small mountain which they can climb and set a signal fire on. There are periodic storms but it is always warm. The only thing bad about the island is really the boys themselves.