To log out of Facebook:
Support KB Category: Login Basics
If you’re having trouble logging in, make sure you enter your entire phone number, including the country code. Leave out any extra zeros, + signs or other special characters.
If you still can’t log in or if you forgot your password, get help.
Note: If you signed up for Facebook from your …
You can log into Facebook using any of the email addresses listed on your account. To add or remove an email address from your account:
If you don’t have a Facebook account, you can sign up for one in a few steps. To sign up for a new account, enter your name and email address or phone number into the form on www.facebook.com. Then, pick a password, enter your birthday and gender, and click Sign Up.