The task is to perform a simple integration between a website and Mailchimp. You can use any programming language that you wish to. However since PHP is your core skill, I would suggest that you use PHP.

a) The detailed steps needed to perform this task are mentioned here. http://apidocs.loginradius.com/docs/mailchimp

b) You would need the LoginRadius PHP SDK. You can find the details here. http://apidocs.loginradius.com/docs/php

c) Please go to https://secure.loginradius.com/account and use the following credentials to log into the LoginRadius account :

 Id : xxxxxxxxx@xxxx.com
 pwd: XXXX16

You would need access to this portal to set up the social login. For e.g for Facebook. The important section that you may need to configure and subsequently look into is the API Configuration section.

##On Confirmation, you'll receive a mail in your Email account. Once you verify the account from the email you receive, you will be added to the subscription list.

 Test MailChimp Account
      testAccountLoginR