As a person who has hired several PAs into their first jobs in TV, I can tell you that just being smart, positive, and expressing your enthusiasm and willingness to work hard without EVER complaining helps a lot.
Networking and being social helps tremendously. Make friends in the business. Inevitably one of them will know someone who knows about a job. Having a name to go with your introduction. Then when you get a shot, don't screw it up. Work hard, learn, don't feel entitled and most importantly make your boss' life easier not harder.
Just my opinion.