Wen welding if it feels to push u away from wot ur welding turn the wire feed down until u get an easy crackle. and the weld seems soak into the pieces welded but not so slow that it fizzies up and drips away (means its too hot ) .
Also on the welder if its got model numbers like 140 turn the power to about halfway or less. that number usually means amps it can do so aim for about 40-45amps
try make the edges to be joined as close as possible if not closed up . It should penetrate through and look clean with it being thin metal
If ya can get some stuff the same thickness and buzz over that so u can see the heat absorption Wen its yellow stop and let it cool .
or turn the power down if ya cant move quick enough
Comfort is the key
Hth and good luck
P.s all this is assuming its a mig welder . If ur using stick on a car gooood luck ull need it