Newbie welder question.

I have a Lincoln Weld-Pak 110. I am not a professional. Not even close to intermediate.... The book and other info I read on using it is that smaller wire is better on thinner metal. I think the metal on my Dart is either 18 or 20 gauge. I practiced before being serious with the .035 wire and had burn through until I had voltage, wire speed, and hand travel speed right.