Welding for the first time - need advice

One thing that helps a lot in all welds but especially when butt welding is to dress the edges of the metal your welding with a grinder. Grind off all burrs or rough edges. These edges have little spurs on them that act like wicks & heat up really quick & start to burn away 1st very fast & that makes it burn through. If you grind it 1st taking away the little spurs it doesn't burn through as quickly. Copper backing really helps too.