What’s the fastest way a person can build a writing portfolio to get hired by some big companies, like Marvel or Disney, or something like that?
beg to stan lee in heaven
Be established with years of experience, work your way up from a small job within those companies, or have a portfolio so good they’d be foolish to turn you down
What job? There are a million. Pull up their company job listings and look at the requirements for jobs you like. Then build that background.
Fastest? Probably by being the best office administrator ever.
If you want a creative job, then you need to work very hard at getting very good at art. More than that, you need to establish a presence, and a backlog of work that proves you can meet deadlines and work with teams and feedback.
Is that how you did it?