Don't talk to anyone that you don't know online. iI could be a someone who does bad stuff.
Don't share passwords. Someone might hack your acount.
Don't do anything bad online. You can get in trouble.
Never tell strangers how you look. They can look for you and kidnap you.
Never talk to strangers. They might be bad people.
Don't say bad language in facebook. You can get blocked.
AND DO NOT EVER POST ANYTHING BAD! You will be in big trouble.