When you have an issue like Facebook not working, the first thing to do is clear out the cache of your browser. How to do this varies depending on your browser.
After you’ve completely cleared out the cache of your browser, then go ahead and restart your computer.
If that doesn’t work, then I would get on another computer and try to load Facebook.
Ultimately, if Facebook is still not working – which would be highly unlikely – then Facebook is down and you’ll just have to wait it out!