Before you start, login to your dashboard and check to see which social accounts are already integrated by navigating to Customize>Contact & Social then clicking the Social tab. From there, you can see which accounts already exist and determine if they need to be updated or not (most clients add social accounts to the system when they are first onboarded, whether or not they actually display them on the social wall).
If you'd like to activate your social wall or update a social account, simply input your social URL and select the box that says "Display on Social Wall" underneath the input field. The option to link to your social wall is available for Twitter, Instagram, and Facebook. The other social media fields, including LinkedIn, Pinterest, Youtube, and Google+ will not show up on your social wall, but can be linked from icons on other areas of your site.
Note: If you have demographic restrictions on your Facebook page (age, location, etc.) posts from that page will not pull to your social wall until you disable the restriction.