Chapter 2 of the story Of Mice and Men introduces us to many difficult characters who we can almost foreshadow to be a problem for Lennie and George.
First, they meet the new boss, who is rough and unwelcoming. When he asks the questions, George answers for Lennie because Lennie is mentally challenged. A climactic moment occurs when Lennie answers a question despite George's efforts to keep him quiet. This is how he got found out about his mental condition, making George quite frustrated.
We also get to know the boss's son, Curly, who was basically pedantic and insecure. He immediately picked on Lennie since he was jealous of Lennie's much bigger size and his attitude immediately brushed George the wrong way. In fact, George immediately knew that he hated him.
Finally, we also meet Curly's wife which it was clear from the get go that she is a tramp and she is trouble. She has probably slept with the field hands and she was more than likely eager to know who are the "two new guys" so she can start causing trouble.
Therefore, Steinbeck really created unease and hostility all through the chapter by introducing at once every obstacle that will come in the way of George and Lennie's dreams, and by making them so unlikeable that one has to say "BOY, what a first day of work!"