Looks pretty good, but I am far from an expert. It's hard to tell if you got good penetration from the pics, but I don't see any deformation where the weld metal meets the stock pieces.
What technique are you using? I like drawing "C"s across the joint between the pieces and pushing the puddle. Gives welds that look more rounded like this:
Yours have a point down the seam. Not saying it's wrong, that's for the experts, but just different than mine. The thing I struggle with most, aside from adjusting the welder, is patience. I really have to slow myself down and make good passes.
