The design of your email sequence will depend on your email template; email templates are for email styling and how it will look when sent. It's basically for customization of font, color, background, header image, or footer.
We have default templates that you can use, but you can only customize It with your preferred design as to what it would show on your broadcast. (Email template link8)
You can also use custom HTML or have someone else make the code for you and use it in your account. More info about that is here8.
As for the email sequence, the guide below will show you how you can set this up. I would recommend that you check out this page; this guide will give you an in-depth tutorial with the feature:
If you have further questions, I recommend you email email@example.com to take a look at your account.