Try to see if you wrote it down or if it is saved in your browser. If not, then you will only be able to reset it, since you can't view your password from Facebook.
Each router has a default password/PIN, and you can check your router for a sticker with that information. If the password has been set to something else, and you've previously...
Try logging in one more time. If it still does not work, try resetting your password once more. If it still doesn't work, then reboot you computer. Then it should...