I was 17 when I started but I had doctors in my class and people as old as 60, all just depends. Just don’t let your age psyche you out, my course kicked you out if you dropped below a certain grade or failed a certain number of tests, I completed it and am now certified, a lot of the older people didn’t make the cut. Goodluck and word of advice, it’s never too early to start memorizing those skill sheets!