How do you get a job at marvel comics?

Marvel maintains a "Careers" web page with information about job openings. See link below.

Like any large corporation, there are a wide variety of positions at Marvel, from receptionists, marketing, sales, writers, artists, production, legal, etc. You'll need to find out what types of positions are available, and then be qualified for them.

If you're interested in a career in comic books, attend comic book conventions and mingle with comic book creators. This will allow you an opportunity to learn more about the business and how to break into it.