welding is a skill not book read knowledge...
the best welders i've ever met were there because they started doing it, pushed through their problems, and got better as they progressed. not a single guy making 100k+ a year doing pipeline or structural welding ever mentioned learning anything from a class (or even going to a class for that matter). the best way to learn welding is to grab the basics from wherever you can, youtube is a good way to learn the basics before you strike an arc, before youtube you walked down the street to the local gearhead building his hotrod and asked him to show you how to start, simpler now that you can type it in and get the same advice to start.
you don't need to know the ins and outs of why welding works, how it happens, to weld decent/good you just need to know the materials, settings, and technique, all of which don't require electrical theory or serious metallurgy insight
(p.s. i was once in the same position, i thought a class would be beneficial because i didn't have a machine to use at one point, and figured that just being able to fiddle around and test different things as well as get some seat time on different machines was going to make me better.... all wrong, buying a midrange machine to start would be most beneficial because you'll get more than 20 minutes a day of time to test and weld things. as time goes on you'll see how much you really don't need a class to get started... the class is a good way to get a job doing minor maintenance stuff somewhere because you can hold up a piece of paper saying you took classes on it, but aside from that. i don't see why you should listen to a guy talk about a skill you should be working on to get better at. you can listen to a guy talk about how to hit a baseball, or you can step into a batting cage, learn the basics in a few minutes and go from there).