When I click "Facebook" it won't load in on page.

Could be a few things. I’d try opening Facebook in a Private Window first. If it loads there, an extension or saved site data is probably causing the problem. If that doesn’t work, try Help → Troubleshoot Mode and load Facebook again. Also check that Firefox isn’t blocking cookies or scripts for Facebook. If you can say what happens when you click it (blank page, error message, spinning forever, etc.) and what version of Firefox you’re using, we can narrow it down.