First you’ll need to make sure MailChimp for WordPress plugin (MC4WP) is installed and active. If it’s not, access Appearance > Install plugins and install it there.
Next you will need to setup a new MailChimp account and create an API key to add in the plugin’s settings to connect with it. Get your API key here.
Access Form in MC4WP plugin, and you should be able to just edit the form. Throughout my demos, i use this HTML markup here:
<p><input type="email" name="EMAIL" placeholder="Your email address" required /></p> <p><input type="submit" value="JOIN" /></p>
As you can see, it’s mostly the same, with different text strings.
If you’re editing the page with Elementor, you should be able to find the Newsletter Form element in the left editor eg: https://d.pr/i/y8WgbM . After you dragged the element into the canvas, make sure to select the Form ID eg: https://d.pr/i/lPt6ds .
Do know you can always make use if it’s shortcode too eg: https://d.pr/i/oMZlhg .
You should be able to find plenty tutorials how to use MailChimp interface and how to send newsletters. Here’s a good starting video https://www.youtube.com/watch?v=Wr-mw_cAn2c .