You can find any welding classes at your local technical college. Mig and tig are the two best for welding. Mig welding would be a majority of your welding. Tig welding is great for exhaust or areas that would contain combusteable materials. Arc welding is dirty and is harder to use on lighter gauge material. I'm a journeyman sheet metal worker and a certified welder. I have experience in mig, tig, and arc including structural welding with stick, spray arc, pulse, and flux core. If you have any questions feel free to ask I am happy to help.
P.S. I also used to do quality control until I got fed up with politics and a majority of my time was spent teaching not only younger guys but also guys who had 20 years more experience welding than I have on proper welding techniques and procedures.
1968 Mustang gt fastback/347 stroker 440hp 425tq/tko600/9" with 3.89