CHAPTER 2 of Lord of the Flies: According to Piggy, what is the first thing they should've done? Why didn't they do it?

In Chapter 2, Piggy loses his temper during an assembly
and screams at the others for not listening to him.  He
says,

The
first thing we out to have made was shelters down there by the beach.  It wasn't half
cold down there in the night.  But the first time Ralph says "fire" you goes howling and
screaming up this here mountain.  Like a pack of
kids!

Piggy goes on to say
that the children will never have any hope of being rescued if they "don't put first
things first and act proper," and he reprimands the children for not respecting Ralph as
a leader.  Piggy also says that because of the children's negligence, the entire island
almost burned. By the end of the chapter, chaos has overtaken the island: the boy with
the birthmark has gone missing (it's presumed that he has been killed in the fire), and
the children are screaming in fear of "snakes."