Intro Component with sign up form using HTML, CSS & JavaScript

What specific areas of your project would you like help with?

I couldn't figure out how to display the error text when clicking the 'Claim your free trial' button. I was able to have the background colour turn red for any input field that doesn't meet the validation requirements or is empty. This would seem to indicate that I wasn't too far off from finding the solution to display the text instead of having the input field background change colour. Any suggestions as to how I could achieve this would be great.