This is a miniature Captain America's Shield that you can attach a magnet, among other things, to the back of and use it to decorate things. I have it hanging on some metal objects in my office. :)
This is a very simple and relatively quick print. You won't need any supports or a raft or anything. It'll just print as is. I printed at 0.1mm layer height due to the tiny details and the curved surface.
As for post printing, I sanded it with 60-400 grit sandpaper to get it smooth, then I painted on the red and blue with water based acrylics paints. For more information on that, watch the video mentioned above.