There are two option that we can use.
1. With those MyThemeShop (If using themes from there Recommended)
2. Or using a JETPACK plugin: https://jetpack.com/support/extra-sidebar-widgets/facebook-like-box-widget/
Follow the instruction.
* You must first click the link above, and activate Jetpack
* After activating the jetpack you can now go to Personalize and choose widgets.
* Click the Facebook Page Plugin (Jetpack) and Add it to widget.
* And you can now customize your widget directly to your facebook account simply paste the URL.