Similar to what others have said, the use of a da polisher is recommended for a beginner when your considering paint correction, but you'll also find that many seasoned veterans continue to use a da almost exclusively. The rotary rotates in a fixed axis and creates an abundance of heat, which could result in burnt or ripped paint, but you also have to look out for buffer swirls and holograms that can also be induced when using a rotary. A da oscillates (small circular motions as is rotates around a larger circular motion). The benefit to using a da can be found in the reduction of heat created (greatly reduced chance of removing paint) and your less likely to induce buffer trailers / holograms.
The best piece of advise I could give to you, is do plenty of research! Everyone here will also suggest, that regardless of your polishing tool, the best thing to do, is begin with the least aggressive combination and work up (only) if needed!
