This is really just a simple matter of hiding and showing groups.

Let’s say you have a group ‘sign up’ where the user signs up.

You then add another group under that called ‘verify’ or whatever you want to call it…and add a text element with whatever you want to say.

When the user clicks the sign up button you have a workflow.

In the workflow, you sign the user up and then add another action to hide the signup group and another action to show the verify group.

Added: Your ‘sign up’ group would be visible on page load and collapsed when hidden. Your ‘verify’ group would not be visible on page load and collapsed when hidden.