Master - detail (one header and multiple lines) input form design using Guided process page template

Summary:

We need to create registration form in below format( image attached).

1st step of should have header information and 2nd step should have line level information where we need to have flexibility to add multiple line under one header (like shown in below image).

Note: We have more than 25 fields on line level

What is the best way design this ?

Thanks in advance.

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

GEN3

Code Snippet (add any code snippets that support your topic, if applicable):