Conflicts belong to every workplace. It is impossible to find a human who never had a conflict with anyone in their life. Even Jesus had some conflicts :).
As an ideal candidate for a position in HR, however, you should be able to solve your own conflicts, as well as conflicts between other people on the workplace.
In your answer you should emphasize that you try to avoid any conflicts. Elaborate on it saying that you are honest and straight in your communication, and always try to understand the point of view of other conflict party.
Talk about the past
This is a behavioral question. You shouldn’t say what you would do to solve a conflict, but rather describe a conflict situation you encountered in the past and how you resolved it. What’s more, you should pick a situation with a happy ending.
If it goes about your first job application, there is no reason to be worried. In that case, all you have to do is to talk about a conflict situation from the school, or from your home. Attitude is what matters, not the situation you describe.
You should always try to present yourself as someone who’s attentive to the needs and feelings of other people. Try to look like a humble person who’s not afraid to admit their own mistakes, and apologize to other human beings.
I try to avoid conflicts with people, being humble and attentive to the needs of the others on the workplace. I had a conflict with my manager in previous job once. He believed I was doing my job ineffectively, but did not realize that I had to wait for the work of other people to be completed to finish my own job. Without that I could not progress. I apologized and tried to explain it in simple language, giving specific reasons why I hadn’t accomplished my duties in time. I understood he was angry. His own superior was not satisfied with the results of his job. After all we came to a conclusion, the workflow was changed and conflict solved.