Good advice here. Learn to "stick weld" first, a Lincoln "tombstone" 225 AC/DC is what I'd recommend or a similar welder. MIG is great, but they don't like dirty metal, but If I had to pick a single good all round welder it'd be a "Stick" welder for general farm use. I've know several guys that ran before they walked and bought a MIG first and when presented with a stick welder because the MIG wouldn't weld it were dead in the water. I'd get a stick welder and try learning the "hard way," trial and error, then take a class at the local community college or trade school if you don't catch on right to start with. Do some reading on metal thickness and rod size. "My" rule of thumb, what ever diameter rod you're using, is the amperage to start with. A 1/8 inch rod is 0.125 diameter, set the amps at 125A, if you're burning through, weld/move faster or lower your amperage. Match you rod size to the metal thickness. Google around on YouTube, it'll help.