Since I grew up in the Los Angeles area, I think almost everyone here considered acting as a career at one point or another in their lives, including me. I got bit by the bug when I was 8 or 9 and got a part in all the school plays all through high school, but my mom wouldn't let me audition for anything more than that. I took some professional classes in college and did some extra work, but auditioning is pretty grueling work and you have to have the self-confidence to withstand constant rejection for the most superficial things. I should probably thank my mom for saving my self-esteem.
One of my friends started out as a techie working backstage and kinda worked his way onto the stage by schmoozing with the producers and directors at parties. But it wasn't steady work, so he still worked backstage and had another part-time job to pay the bills and save up enough money to move to New York to do theater, since LA doesn't really have a thriving theater community. He finally had too many on-camera hours working as an extra so he either had to join SAG and pay their dues or stop doing any film or tv gigs. He's been in New York for over a year now, mostly taking classes and auditioning, but the competition is really tough.
It's always a good idea to have something to fall back on if your career doesn't pan out. Education is a great one since you have so much time off during the summer and your work day ends pretty early so you could possibly make it to some casting calls. I would do as the Queen of Evil suggests and take some improv classes. Most of the auditions that I went to handed you the script when you got there and you were expected to read off it rather than a prepared piece. It kinda sucks for us actors, but it's easier for them to compare the differences. My instructors always told me to try interpreting the piece in as unusual a way as possible, especially since they give you a pretty bare backstory if they give you one at all.
Good luck in your endeavor and I hope you're one of the lucky ones that make it!