I'm currently brainstorming a fantasy story, and I love the idea of my main character, but I'm having a hard time pinning down who she is as a person. I know her backstory, her family, her abilities, even her job, but for the life of me I can't figure out what her goal is. I can't figure out what she wants out of her life, and I don't know how to solve my problem. Any suggestions would be super helpful.
You may not need an overall goal. You may be able to discover this as you write.
Try this: Give her a problem. Any problem will do. She will try to solve it. When she does, arrange for her to fail. And arrange for the failure to make things worse instead of better.
When she tries again, arrange for that to fail, and to make things worse. And so on.
As she struggles with the worsening situation, you will learn more about who she is by the way she tries to solve the problem, and by her reactions to the failures.
Try to arrange for the failures to force her to choose between painful options. Maybe she can have only one of the things she wants, and choosing one means she cannot have the other. Or perhaps she must choose between two terrible options.
As she chooses, you will learn more and more about what she cares about most deeply.
At some point, arrange for things to worsen in a way that relates to her abilities or background or personality. As things get worse because of who she is, she will have to confront who she is in order to make progress. As she learns who she is, you will too.
So you can discover what she wants as you write. You don't necessarily need to know before you begin writing.
If you don't have a goal for your character... maybe you have made them too perfect? A common theme to help provide character goals is to demonstrate character growth. Give them a couple flaws. Say that she is an elf and a really good magic user, but no one gives her a chance because she is female and she is not assertive enough to challenge people that tell her to go away. In the end, the goal of the MC is usually the punch line of your story. It's the lesson learned or will have to be learned in order to achieve the goal. There may be many side goals or side plots that helps build the main goal, but ultimately, your character is trying to strive to achieve something. World fame? Is there an evil person in your story that is trying to do harm? What does the opposition look like? What is it that they are trying to do to hinder your main character? If you don't have an antagonist, maybe developing an antagonist's character will help you realize the goal of the MC.
Story is driven by desire and that which stands in the way of achieving desire. If your character had a strong desire, she would have a goal. If she does not have a strong desire, that means she has everything she wants. Or at least she has everything she is willing to work hard to get.
That's fine. Lots of stories start like that. And the answer is simple enough. Take something away from her, or threaten to: home, loved ones, etc. Bingo, now she has a goal: either to save them or to be revenged on those who took them.
There are some very good answers here, but hopefully the following can work as an addition or substitute to certain elements.
I have a theory (someone else probably thought of it before me) that characters with a personality and traits similar to the writer can be difficult to create goals for. Is your character by any chance similar to or based on yourself to some degree?
I'm sure there are countless scenarios where a character's overall goal can be difficult to figure out, but for this I will focus on the scenario mentioned above.
If, as @MarkBaker mentions:
"your character has everything she wants"
or as @ggiaquin asks:
"..maybe your character is too perfect?"
I would argue that this character is in her comfort zone. We may not realize that the MC needs something, because she is placed in a context where she does well or is in balance. One way to create or figure out your MC's goal could be to pull her out of said comfort zone.
Sure, this could be forced by some troublesome, threatening or painful experience or treatment which she then needs to act upon, but in my opinion it doesn't have to be that dramatic, unless of course 'dramatic' is what you are going for.
Another way to pull someone out of their comfort zone is to introduce them to something og someone new. She may get a new co-worker that actually asks questions about "the routines" or "how one should behave", she may find that the street behind her house has an abandoned building with something intriguing about it. She may be brought to a friend's party only to realize that she knows no-one and has to mingle within a new social group.
These are just examples off the top of my head, but think of scenarios where you would feel "out of your comfort zone". Maybe introducing your MC to such experiences (based on your understanding of her) may reveal a new goal for her.
A natural progression in the story could then be based on @DaleHartleyEmery's order of "attempts and failures".
Put aside the character for a moment, and ask yourself how you want the story to end. Then work backwards to your character. If she is, in fact, your main character, she will have, or develop, a goal that is congruent with the story goal.
If you can't do this, maybe you should put your "main character" in a different role, and get another main character. For instance, if your "main character" has everything she wants and all the abilities to get them, maybe you should make her the equivalent of a fairy godmother or good witch of the north (that's perfectly fine), and find yourself a "Cinderella" or a "Dorothy."
Readers see a story through the eyes of a main character. Her success/failure ultimately reflects on the story itself. That's why she needs a goal congruent with the story's goal.
Thre is no such thing as an overall goal for a person (other than to be happy, blah, blah). Any person, whether a real one or a fictional character, has a slew of simultaneous goals, ranging from making it to the bathroom on a morning after a party the night before to a getting a multi-million government contract for developing a uberdrive for faster-than-light travel (now try to go to that meeting having a pounding hangover headache and land that job).
Our goals change with everything the life and the Universe throw at us time after time.
What you might try is to explore, how your hero would react to a challenging situation. You say you know her abilities? Offer her something which she is not equipped to handle, and see what she does.
She has a job? Fire her.
She has a family? Kill them ruthlessly in a suspicious car crash.
She has magic powers? Fire her, kill her family, and make her drink something on that party the night before, which negates her magic to the point that it might not come back at all.
Then see what happens.
You are the creator and the owner of her Universe. If you want to know what her goals are, you can do whatever you wish to flush them out.
Use what you (or people you know) wanted. When I had trouble with making a crush for my main character I friended one of my favorite authors on Facebook and asked her how she got the idea of the crush from my favorite trilogy by her and she said that he was based off of her crush from when she was in high school. So think of the main character as yourself or someone you know. It helps immensely.