Modal on load, capture email as form data, complete form, then submit all data

Hello, I am trying to accomplish the following:

• A modal comes up on load asking for an email address
• The user enters their email address and it is captured as form data
• The modal closes and the user is presented with 3 options, each with a button
• The user clicks one of the 3 buttons, and which button they clicked is captured as form data
• The user is presented with another 3 options, each with a button
• The user clicks one of the 3 buttons, and which button they clicked is captured as form data
• The form is automatically submitted with (1) the user's email, (2) the user's first click, and (3) the users second click

Help is appreciated. Thanks!

As an alternative to this question, what if I had the form all contained on one page, but I wanted the user's first selection to affect what the next option they are presented with is?

Step 1 - Choose X
The user selects option 1, 2, or 3 (say it's a radio selection)

Depending on which option they pick, either Step 2 - Choose Y or Step 2 - Choose Z is revealed

All of their selections are form data, and they can ultimately fill out more fields and click submit.

That seems easier to accomplish? The key is that I need to be able to identify the user's selection at Step 1 in order to determine what to present them with at Step 2, etc.

Thanks so much in advance for your help.