If you recently get back your Facebook account form hacking, then we highly recommended that you must learn your Facebook settings to avoid locked out of facebook hacked:-
1. Go to Settings > General, update your contacts information's and add email address and mobile numbers you have access to. Remove those email and mobile number those you no longer have access it.
2. go to Settings > Security and Login to set up extra security two factor authentication to choose two to five trusted friends who can help you to recover your Facebook account when you get locked out.
3. Go To settings > Privacy, select the privacy settings your are comfortable with. Choose only friends see your future posts.
For more details, visit How to Recover a Hacked Facebook Account?