I don’t think one is ever too old to start acting. I know professional actors who didn’t get started until they were almost done with college.
I also understand that acting programs can be expensive. Ask about financial assistance. There’s no harm in asking. But also, look for opportunities in school. Is there a drama club? Is there a speech and debate team? How about a show choir?
Acting is about doing, so find some way to do it anywhere you can! I asked teachers if I can do a presentation instead of writing a paper. I joined clubs where they might be doing skits.
And if you feel like studying acting, major in theater in college.
As a career choice, no I wouldn’t say it’s a secure job choice. But life isn’t just about security, is it? It’s also about deciding your lifestyle, finding your tribe, doing what you love.
And the craziest part is, you can change your mind! No choices are permanent. I had a classmate get an MFA in acting only to become an anesthesiologist after! Go with your gut, take a chance, be brave. You’re young, you’ve got plenty of time.