Passing Data from a Form to Pop Up Form

Here the situation I am looking help for. I have form with input field email and then button get started. When user will put his/her email and click on get started a pop up form will open with more details.

Now, What I am looking to do is to pass that email from first form to pop up form so that user doesn’t have to type email again and when user submit pop up form user will be greeted thank you and data from both the forms will be sent to admin.
I am looking for help from experts to achieve this.