You need to install Facebook in order to use it on your mobile phone. Before you can install Facebook, you need to set up your mobile phone for internet and activate your user account on your mobile phone.
Find "Play Store"
Tap Play Store.
Tap the search field.
Key in Facebook and tap the search icon.
Tap INSTALL and wait while Facebook is installed.
Return to the home screen
Tap the Home key to return to the home screen.