I learned to weld awhile back, but haven't pulled the trigger on purchasing all the stuff I need.
After learning, I'd have to agree with one of the other responses, learning by Youtube is probably feasible. It's safer than I expected (less concern about touching metal in the ground path) though I'd strongly recommend investing in quality gloves, a quality helmet, and good thick pants, and a long-sleeved shirt / overcoat.
I thought about taking a course but I found this way of learning a lot more fun and engaging (if you're fortunate, as I am, to have experienced people in your life).
ie galvanised stuff generates gaseous tin or zinc (~white smoke, i don't remember which). Bad in a confined space like a shed or garage.
So there are some non-obvious considerations that Youtube video's don't seem to mention. :(
something like this works well.
for thin steel or aluminum you really do need shielding gas.
To fit on a trailer (the mushroom's cap is 11.5ft wide) the cap comes off the stem and the edges of the cap are two half-moons which have fixed mounting points where threaded rod sticks through some welded washers, and a nut is put on in place. I was too last minute to install the 200 WS2811 pixels and have them run some cool patterns, before the music festival I brought it to came time, but even just a lantern on top (another painters tarp covered the cap's metal-frame, and everything was spray painted) looked great.
Super fun project. Expensive, but I learned a lot, got to be creative, and I'm happy to try out new things and make the best of my before-children time. Also, it was such a joy seeing people croud around the mushroom (and site beside the mushroom man inside) at night during the festival.