I was thinking of going to school to be a gunsmith.Do they make a decent living? Is it a decent job? Or would it be the type of job where it pays the bills and you need a second job for fun money?

You may even need a 2nd job just to pay the bills. Make it your hobby unless it's your passion and you consider yourself truly gifted with firearms. By that I mean you'll need a specialty such as custom stock building or some other niche. If you're interested in making a career out of working on military/LE type arms, consider going through a Colt certified school or enter the military as an armorer. Just my 2 cents.