Most of those show a lack of gas coverage.
Are you using disposable cylinders or are you welding outside?
That steel is too thin to practice on too, get some thicker stuff to play with until you've got more experience.
@EngHK pure argon does not work well when MIG welding mild steel far better with suggestions above allso welding outside with MIG can cause serious problems as if there is any breeze at all it will blow the shielding gas away from the weld I would change your gas to the recommend then post some more pics up for the panel to pass judgement on