If you are an amateur, metallic paints, especially silver, are the hardest to get a good finish with, as the grain of the metal particles will vary with distance and thickness of coat and make it look patchy . Practice on some boxes and biscuit tins until you think you are perfect.
It can be done with aerosol paints; in which case, mask off well; cover everything in the room that you don't want paint on (including the floor) or do it outside on a day when there is absolutely no wind or insects. Have some little jars handy with thinners in to put the spray nozzles in when they get clogged. Wear plastic gloves (not rubber which will dissolve).
Prepare well - dead smooth clean surface. Apply primers which are easier than finish coats and smooth off with extra fine wet and dry.
Apply several thin coats. When you don't follow this advice leave it to go fully hard for a few days and smooth off the runs, sags and orange peel with your wet and dry and start again.
If you are painting small items, put them on a stand inside a cardboard box and spray them inside that, to protect from wind and dust. Turn them between coats. Paint the backs before the fronts.
Alternatively, pay someone else to do it. Or, if you are a skilled brush-painter, it is possible to get a very smooth finish on a steel surface.