For $20 you can get a wax spreader and remover at WM. Let the machine and product do the work instead of your arms. Use the foam bonnet to apply the wax or sealant. Then switch to the microfiber bonnet for removal.
The rotary that you have will do a good job of polishing. Which is what gets rid of scratches, microscratches, spider webbing and swirls. When starting out use it on one of the lower speeds and that should keep you out of trouble.
You can also by some door skins or hoods cheaply at the junk yard to practice on. Start out on a small area. Buff off with a plush microfiber. Then wipe with rubbing alcohol to remove the oils from the polish.