In Act I of Death of a Salesman, what do we learn about Willy and change?It seems that he doesn't fare well with change and he expects for things to always be the same, but I'm not sure.
Act I of Death of a Salesman emphasizes the many changes that are surrounding Willy although perhaps not elaborating on them in detail. The root change that is instrumental to some of the other changes is that Willy's company has, for an as yet unstated purpose, removed Willy, after decades of productive and faithful employment, from salary and made his wages strictly commission-based earnings (commission: a percentage of total individual sales).
Other changes surrounding Willy are his difficulty driving. He has had several accidents and the play opens with Willy coming home in the dead of the night as a result of an aborted sales trip to Boston: Willy got only as far as Yonkers before turning around and going back home. Willy's wife suspects that at the root of these particular changes lies Willy's newly sprung contemplation on ending his life. she suspects the accidents were intentional and that he has plans to asphyxiate himself with gas. These changes relate to the changes affecting Willy's employment.
Another change relates to his sons Biff and Happy, names which symbolically illustrate Willy's accustomed and innate mental state. Only a happy and confidently successful man could call his children Biff and Happy, indicating that (1) the things Willy says about his decades-long career as a salesman throughout the play are true and that (2) the current moroseness and instability in Willy's mental and emotional state are changes of a dramatic degree. Regarding his sons, Biff has come home for a visit, but Happy is attempting to persuade him to make the return a permanent one, especially in light of Willy's strange behavior on which they eavesdrop during the night that opens the play.
You can see from the cause of the root change that Willy is, indeed, not faring well with the change that the play surrounds him with. Who knows but what he may have fared better with change early in his life when the changes were not life and esteem and livelihood threatening. You are correct in concluding that Willy wants things he knows and loves, things that have helped him prosper or demonstrated that he has prospered, things that have gained him a respectable livelihood to remain unchanged.
The word "expects" may be applicable to Willy's thoughts and feelings relating to the changes around him in the sense that while he was prosperous it never occurred to him that he could one day be overcome and overwhelmed by all-pervasive change. At the time of the play, however, perhaps "desires" or "needs" or "wants" would be more appropriate word choices for what Willy is experiencing emotionally, mentally, and psychologically.