I need to build an email list to a launch of a new online course

I need to build an email list for a new digital / online course I am building – my target market can be located anywhere in the world as being an online course is doesn’t matter on location.

They should be predominantly english speakers as the the course will be in english.

I need to know what you need in order to build a list

Once built we will have a pre – launch sequence through a quiz funnel and then sign up to a webinar that sells the course.