@Vegemite – I just got into a college for flight engineering. You can take some of the courses online, but any courses that require hands on time with actual plane parts cannot be taken online (and even if they could, I wouldn’t recommend it).
You’ll need to take courses in flight dynamics and control, embedded control systems, and analysis of dynamic systems, just to name a few.
I suggest looking into aviation schools around the country. Most of them offer a flight engineering program.
By the way, in order to become a flight engineer, you have to have a high school diploma, two years of college education (a Bachelor’s degree is better), a commercial pilot’s license, and a certificate from the Federal Aviation Administration.