Step 1: Go to https://developers.facebook.com/docs/plugins/page-plugin/ while you're logged in and hover over "My Apps" and click "Create New App". Fill in privacy and terms URL and other basic settings.
Step 2: Go back to https://developers.facebook.com/docs/plugins/page-plugin/
Step 3: Paste your facebook page URL in the text box and customize and other variables you see fit.
Step 5: Go to your CMS Max dashboard, Settings >> Global Scripts. Then click Add Global Script. Give it a name such as "Facebook Page Plugin" and select "Head" for position. Then copy and paste the step 2 from the facebook popup into the content area like the screenshot below. Then click Save.
Step 6: From the step 3 in the facebook popup window, copy and paste that code anywhere you want into the CMS Max page (but click the source icon on the toolbar first).
Ask us for help as this is more of an advanced feature.