How can I act regarding my desire to marry a specific girl whom my family approves of, while my father insists that I marry another girl whom I do not desire?

If the girl is religious and of good character, try to convince your father, citing the Hadith: "A woman is married for four reasons: for her wealth, for her lineage, for her beauty, and for her religion. So, choose the religious woman, and you will prosper." Explain to him that your marriage to someone you do not love is not in your best interest, and seek help from someone who has influence over him. Pray to Allah to guide you to what is right. If persuasion proves difficult, then obey his command, because marrying someone your father dislikes may harm your relationship. The right of a parent is great, and Allah has coupled showing kindness to them with not associating partners with Him, and has linked showing gratitude to Him with showing gratitude to one's parents.