It depends on what you're trying to do. Are you just trying to set Open Graph tags for your home page? If so, you can add the {SCOpenGraph title=My Title} or description or image, etc tags to any content that will display on the page. That can be in a module, article content or somewhere else. One common thing to do is create a Custom HTML module and insert your tags there.
I hope that helps, but if there's something else you were looking to do, please let us know more details.
Thanks,
Alex