Any job in the entertainment industry is very competitive. Even graduates from top film schools like USC, UCLA, and NYU work as assistants (not assistant directors) for years. (Film programs like USC only admit about 5% of applicants, after being admitted to the college, an 18% admit rate.) Some crew members are in unions, it is very tough to get those jobs and join unions. If you aren't already living in this country and are legal to work, it is impossible to get a job here. In that case, start where you are now.