Set up a automated welcome email for the customers who signed up from my landing page

Hi everyone, I have an existing landing page (with mobile responsive) but still need to request some amendments: Task 1: Fix the landing page (includes mobile responsive) signup button - Ensure the users can sign up the newsletter instead of tabbing a new link to re-type the info again; and it integrates the data to my Chimpmail data pool. Task 2: Create a welcome email - We have the layout and creative, just need your help to set it up. :) Task 3: Create the automation - We want it to be worked automatically; which means my customers will receive an automatic welcome email (task 2) once they have key in their email in the sign up button I need it to be done by today, thanks. :)