For a new painter, I would also recommend an HVLP(high volume, low pressure) spray gun/rig. They allow you to float on a lot more paint with a lot less over spray.
Some of the pinholes in your paint, are called "fish eyes" and are caused by contaminants on the surface. Any silicone from lubricants, waxes, etc, can ruin a paint job, which is why you must use the proper paint prep to clean the surface BEFORE you do any sanding. Then they have a fish eye reducer that you should add to the paint to minimize them showing up on the surface.