First you'll have to study the career, if you're still wanting to continue, proceed to talk to people already in the field, begin to acquire the necessary skills if you don't already have them and apply to jobs.
Career security is having the education and experience enough to know and be confident in the fact that you can go anywhere and work in your selected field provided your field is in need where ever...
If you are still a student, there may be school plays in which you could appear. If not, go to auditions and apply, get an agent, look for work, and act when you can. It can be a tough line of work,...