George becomes mad at Lennie in the first scene because lennie just seems to do everything wrong. Lennie is never satisfied with what they have, and can't remember anything that has happened or plan to happen apart from their dream. However this anger George shows only tell us that George feels responsible in a way for Lennie and acts like a advisory.
George and lennie make it to their destination and meets everyone. However the bosses son curely and george start out on a bad foot. Curely gives lennie a hard time because he wants to assert dominance because he feels threatened by lennies appearance. This goes to show that curely has authority issues, and has to feel in charge at all times for him to feel important.
In these chapters a lot of death occurs. First lennie kills curelys wife accidentally, not meaning to because all he wanted to was feel her hair after she offered. Then out of fear of getting into trouble he left and ran to the spot George told him to run if he ever got into trouble. After lennie went left a search part was released to find and kill him. In the end however george killed lennie to save future lives that may be taken becuase of lennie. This just goes to show how at this time period many didn't know what a disability was and how it affected a person. So they definetley didn't know how to handle someone with a disability.