How to develop an acting career, starting as a background artist
We've all got to start somewhere and working as a background isn't a bad start, after all, you'll gain experience of being on a film set and actually see how long it takes to put a tiny part of a production together. Once you're there, learn from the actors, assistant directors and of course the Director and not forgetting the producers if you get to see them. Always be early, at least fifteen minutes before your call time. I know of one BBC production where, if you're five minutes late, they'll not only send you home, but you won't get booked onto that particular production again.
You can read lots of books telling you how it all works but there's nothing like learning from being right there in the middle of it all.
Network with other artists, (off set), don't do it on set in the middle of a rehearsal or you won't be asked back! You can learn a lot about what's happening locally to help you move upwards in relation to courses, agents and auditions/castings etc just by asking a listening to other people, artists and crew!
If you work well on the day with directors, crew artists, you'll probably get re-booked on their next project, which is money in the bank and could be a more important role where there are just a few of back ground artists instead of 30-40 plus and your name will be on the call sheet!
From there on, through networking, taking extra classes and being available, sometimes at short notice, you'll be able to decide on which area you'd like to work in, whether it's theatre, film or another area of the performing arts and promote yourself in that particular field. You might start out aiming to be Gods gift to the acting world and aim to achieve it in a year and then realize that it's not that easy, just by watching the professionals at work in front of a live studio audience and going out live on national television.