Enrolment

I'll try to ask this the simplest way possible...(if I could...)

Objective:
Client enrol sending an email to me (Administrator) to a course using paypal payment, AFTER having access to a FREE COURSE.

Description:
I created a Category for the Courses where there are 4 courses as follows:
Course 1 is Free
Courses 2, 3 and 4 are paid separately for each course the client chooses to do.

I want to give access sending username and password to EVERYONE whoo filled in a questionnaire and personal data. I suppose I need to give GUEST ACCESS so everybody on the internet has access to this questionnaire,
Q-1 Correct?
Q-2 Do I need to create a course for this purpose only?

Q-3 If the GUEST answers a questionnaire can it be emailed to me (Administrator)?

I know this is complicated and I'm not sure here is the place for so many questions, but I'll be more than happy to get a bunch of links or a book where to learn how to do this.

Kind Regard to all

Beto Boton