The goal of your novel, whether big or small is expressed early on with your protagonist, and your novel's goal is to prove or disprove it.
When dealing with characters, there are two types of motivation and conflict that run parallel throughout a story: internal and external. The external motivation is the main protagonist's stated goal that she wants to accomplish by the end of the story, and the external conflicts are the events and circumstances that stand in the character's way. The internal motivation and conflict are difficult to see and are usually subtle, but become more apparent as the story unfolds. The internal motivation is what the character wants personally, while the external motivation and conflict help to reveal those desires more clearly. The internal conflicts are doubts and fears that put the goal at risk.
On a high level, think about your main protagonist's internal and external motivations and conflicts and use this as your guide to tell your story. Being aware of these elements to your story will foster cohesiveness and present a narrative that is relatable. This process allows you to map out your character arc, supplying your character with specific wants and goals, then putting obstacles in her way. The two basic ways a character arc unfolds, is whether they achieve the goal or not. The degree to which the character is successful or not in achieving the goal reveals something about the character as a person, and ideally, something about ourselves as the reader.
As you develop your characters, make sure their internal and external motivations are clear as they are the driving components to your novel. Your goal should be to draw your reader in with characters that are relatable, or are drawn with detail so your reader can understand the internal and external motivations.