Spot welding is not the same thing as welding. A spot welder shorts a high discharge dc current across two electrodes to melt nickel strips to the battery terminals to connect them. It does not use gas or flux, nor does it consume the tips of the electrodes.
It is both considerably easier to learn than real welding and the equipment is considerably cheaper. I think I paid around $125 for my k weld, plus another 40 bucks for the high discharge lipo to run it and another 20 for a charger for the lipo. It is not anywhere close to real welding in complexity or cost, and you can learn in one afternoon.