Adding custom section on form

Hello. How can I made form(for user enter) like this:

organization name
organization phone
organization address

user #1
user first name
user second name
user email

user #2
user first name
user second name
user email

....

user #N
user first name
user second name
user email

How made this form and save data to email and DB?

Also I need buttons to add collection item and delete them