All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
If your work does not involve any religious prohibition, like forbidden mixing, being in seclusion with men, touching men and the like, and your father ordered you to work in the restaurant, then you should obey him. However, if he did not order you to work in the restaurant and gave you the choice either to work with him or to study, then there is no harm on you to choose what benefits you. Achieving the interest of the child does not mean hindering the duty of being kind and dutiful to the father. If it is possible to help your father at work and follow your studies, then this is better.
Allaah Knows best.