I am a man who is not good at understanding people's feelings. How do I learn to respond to my wife's emotions before marrying?

This skill can be learned, and its first step is listening to understand, not to solve. Many men jump to giving solutions when a loved one complains, when what is needed is to feel heard. Practise now with your mother or siblings. When they tell you something, repeat back what you heard, for example, ‘So you are tired because all the work falls on you?’ Then ask, ‘Do you want me just to listen, or do you want suggestions?’ This question will be very useful in marriage. Allah reminded His Messenger: “Had you been harsh and hard-hearted, they would have dispersed from around you” (Surah Ali 'Imran 3:159). See communication & emotions.