Follow that step below to help you can collect email of subscribers.
Step 3 - Navigate to MailChimp for WP > MailChimp then connect with your mailchimp account you created from step 1 .
Step 4 - Create mailchimp form to collect email. Navigate to Forms
Import HTML Code below on section Form mark-up Source
<h3 class="screen-reader-text">New Letter</h3>
<input id="mc4wp_email" class="form-control" name="EMAIL" required="required" type="email" placeholder="Enter your E-mail" />
<button type="submit" class="btn-subscibe">subscribe</button>
Step 5 - After creating from of your plugin. You must set position where you want to display.
Going Appearance -> Widgets then drag mailchimp widget to Newsletter Sidebar. You can bring that sidebar to every position you want. ( You can drag to left, right sidebar for each page. You can drag to Footer position.... )