Why is Trevor worried about leaving on page 63, and how is he trying to survive?

Trevor is worried about having to leave. His mother has not been home and the landlord keeps knocking on their door telling them they have to pay or leave. Trevor has been hiding so the landlord does not see him. He has been betting to try to make rent money. However, he has been spending that money on lunch at school and hiding half of his lunch to save for dinner.