How to Paint a Door With Primer
Paint provides an almost instant update to an old door. Both interior and exterior doors look better with fresh paint, but proper application is vital so the paint goes on smooth and doesn't peel off. Primer hides slight imperfections or old finish while providing a smooth, clean surface for the new paint. Wood doors need an oil-based primer and paint because standard water-based latex paints can cause the wood grain to rise.
Paint metal doors using the same technique used for wood doors, but use a primer formulated for metal instead.
Select a primer similar in shade to the final paint color, such as a white primer for a white door or a gray primer for a blue door.
You will have a wonderful home after painting, Hope you do good, you can do it.