It's always useful to have your main characters in a dilemma.
Does your hero have an unfulfilled desire? Does this drive him or her to try and achieve it? What about two simultaneous desires that conflict, contending with each other for his or her mind and heart?
In almost any good story one thing must be given up to gain another. Your main characters will have to decide which one's better.
Let's go with some public domain fairy tales, ok?
What does the third pig give up to gain protection from the wolf? His playtime. He works longer and harder than his two brothers and gains a safe place to live. Did he want both playtime and safety? Undoubtedly, but he chose one over the other.
What did the wicked queen want in Snow White? She wanted to be the best and to eliminate any possible competition. Yes, even villains must make choices about how to go about obtaining their desires. And what did she give up to try and obtain it? Her beauty. It was supposed to be temporary, of course, this disguise as a harmless beggar carrying apples. Nonetheless, in going to such lengths to be seen as the most beautiful, she put aside her beauty in an attempt to deceive her competitor.
What did Dick Whittington desire? He wanted to be free from an abusive lifestyle. Why did he go back to the house where he was having such a very difficult time? Because the bells sang to him that he would become Lord Mayor of London, and he believed them. His desire to succeed and arrive at a good place in life superseded his desire to get away from those who were treating him unkindly.
And so it goes. Find some of your own.