Hey man it is not too shabby. I would say if you don't
want to buy photoshop there are plenty
amazing plugins for ms paint that can make it feel
like any other program. If you cba downloading plugins
I would recommend gimp (latest version)
Now for the artwork the anatomy is off. I would line
up the head with the neck. Also your neck should line up with the line on the chest (for the most part)
Speaking of that collar bone line it should be curved up instead of downward like you have it