Does the png you try to submit comes straight from render? Maybe taking it in photoshop and then save it back into your prefered format would make a difference…
As for your legs, I always have trouble myself modeling them, so I can’t help you a whole bunch. The best advice I got would be to grab as much reference as possible, which is what I always do. Right now they look okay, yet somewhat squarish - but hey, who am I to criticize an “absolute very first time” leg-modeling attempt…
Keep it up, mate! It’s great to follow your progress.