Not OP, but I learned MIG at my local community college about 15 years ago. It was mostly pipe-fitters getting certified in the class and I was able work on whatever projects I wanted. I started with stick, then went to MIG, and then did a follow on class where I told them I just wanted to do Oxy-Ace. I think now they offer a more variety of classes, for people who want to do art and such.

If I recall, flux core is dirtier, and having a tank of argon on your cart isn't too expensive for a shielding gas. I lived in a studio and luckily my neighbors were cool with me running a chops saw.