Agree with Evil pushing will give you better gas shielding coverage.
Cant tell for sure if this joint attempt was overlapped or butt welded?
If doing this as a butt weld I would start on 2 (low) and place several tack welds along the joint every few inches. This ensures the heat doesn't pull the work pieces apart as you try to place a run of weld.
Then start to join the tacks up with beads of weld possibly upping the power to 3 (low) Welding two sheets together you should push and also weave / zig zag between the two sheets keeping an eye on how much heat is being generated.