Welding noob, hows this one or other suggestions

Sheet metal is tough to begin on, very thin and you can burn through it very quickly. 1/4 steel is very EZ to weld, header pipe is almost impossible for a beginner, especially 18G thin crap that is rusty and already thinned from years of use. Good luck, practice practive practive. Get a good auto darkening helmet too. Very useful.