There are bullies in all walks of life. Best to ignore them. Practice makes perfect and cars in general are not the best place to learn how to weld properly. The thin metal and the corrosion make it a soulless task sometimes. But well done at what you achieved but if you practised on some thicker stuff you will learn even more and be able to feed that back into the thin stuff. Remember that cleanliness is paramount when welding and keeping the earth as near to the point of striking is important too.