Link mailchimp to my newsletter sign up form

Question

I've built and hosted on github a simple static landing page (html & css codes are from Launchaco, a lading page builder). What I want to do from here is link the current newsletter sign up form (no input possible now) to my mailchimp account to allow new signups.

I'm a complete beginner in coding but after some research, I've found a pretty good tutorial (http://kb.mailchimp.com/lists/signup-forms/host-your-own-signup-forms) to host custom sign up forms. I've created my test signup form but don't really know how to insert the code source to the existing website.

Currently, the code for my signup form is as follow :

 <input class="ctas-input" type="text" placeholder="Your Email Address">
        <button class="ctas-button">
          Sign Up
        </button>

I'm a bit confused of how should I properly input the mailchimp signup form code to make it work. From the mailchimp tutorial, I should inject this into my current html :

<form action="https://wordpress.us7.list-manage.com/subscribe/post" method="POST">
<input type="hidden" name="u" value="d738b1c4cd4fa317c48b7b752">
<input type="hidden" name="id" value="d079621c26">

<div class="mergeRow dojoDndItem mergeRow-email" id="mergeRow-0">
        <label for="MERGE0">Your mail adress <span class="req asterisk">*</span></label>
        <div class="field-group">
            <input type="email" autocapitalize="off" autocorrect="off" name="MERGE0" id="MERGE0" size="25" value="">

      </div>

If you have any ideas, I would really appreciate !

Thanks and Merry Xmas