I am blind in the dark and can barely tack weld with a MIG, but I see a lot of broken stuff and I will say that "pretty" welds doesn't mean anything. I get plenty of cars in with awesome looking welds that have cracked within a week of actual use on a car. It seems like everyone on the interwebz drools over pretty looking welding and bags on ugly welds(which often are perfectly fine, will hold, and will pass tech). I see a lot of exhaust manifold with nice looking welds that didn't have even close to enough penetration and crack after a few real heat cycles. People try to MIG weld intercooler piping also, which often leaves hundreds of pinhole boost leaks around each weld. Just have your brother teach you.
I tried to learn for a long time, but then later found out that I have an eye disease and can't actually see worth a shit compared to normal people, so I leave that to other people.