The first page opens by setting the scene of this strange dystopian community of which Jonas is a part by explaining the fear or nervousness that Jonas has in his heart. It reminds him of the fear he felt when, a year ago, an unidentified aircraft had flown over the community twice and the fascination which quickly turned to fear that he experienced as he tells us that this was against the rules of the community. The plane was different from the normal planes that they see and both adults and children were confused and frightened by what they saw. The response they received did nothing to calm them down:
Then all of the citizens had been ordered to go into the nearest building and stay there. Immediately, the rasping voice through the speakers had said. Leave your bicycles where they are.
Such an event shows the very closed nature of the community of which Jonas is a part and how tightly controlled it is. Jonas and the citizens are obviously conditioned to obey and to obey immediately. The opening of the story thus serves to set the context for the rest of the novel as we discover more of the rigidly organised community of which Jonas is a part.
Personally, I didn't like the beginning of the Giver. It felt really cheap and cheezy (or as I like to call it: Chintzy) and it felt just kind of generic. It starts with Jonas walking around his community and he's talking about a jet that flew overhead his community. Then the author can't find the word she's looking for, so it turns into a paragraph long spiel about the word apprehensive.