What are Beneatha's hopes for her future? Why is Walter concerned about Beneatha's plans?(A RAISIN IN THE SUN: ACT 1: SCENE 1)

Beneatha plans to study medicine and this worries Walter because of money.

Explanation:

According to Walter, Beneatha should dedicate herself to something else and not study medicine. Walter's concern comes from the family's lack of money, and Beneatha's chosen career means a part of the check they will receive for the death of their father.

This causes Walter and Beneatha to argue since she disagrees with him and maintains that her mother will do whatever she wants because that is her money.