Here are some points for you to think about.
To get the most from a polisher such as Harbor Freight or the Porter Cable, you would do better if you use smaller pads (5.5 inch) since this would minimize the machine from bogging down but this does require you buying a smaller backing plate.
Prior to buffing, the car should be wash and clay. A Foam pad on a DA polisher will not remove the surface contaminants on the car. A wool pad, a heavy cut compound, and a rotary could....in the right hands.
To buff out an average size car requires 3-4 pads (the more the better). If you are to do any corrections beyond polishing then you are looking at minimum of something like this...... 3-4 (Orange), 3-4 (White), 3-4 (Black). You will also need a brush to clean the pad between each panels as well as some good microfiber towels (not the costco ones) to wipe off the polish on the car.
The combination of the polish, pads, and the action of the machine will determine the aggressiveness of the approach. For starters, go with the OTC Meguiar's Ultimate Compound and Polish. These 2 products will be much easier for a beginner to deal with. This brings up the most important point.
Technique. There is more to paint corrections then just buying a polisher, some Pads and a few polishes. Good techniques could overcome inferior products but no products can overcome bad techniques. Read up on the Kevin Brown Method.
2nd most important point. Do a 1' by 1' test spot to make sure your entire process is the correct approach. You don't want to buff out the entire car to find later that your process was no good.
If you like to learn more.... check out some dedicated detailing forums such as AutoGeekOnline and Autopia.
Please don't think I am trying to discourage you. I am not. I am trying to help you to plan the process out. You could either learn from your own mistakes or...... learn from the mistakes of others.
What is absolute control???? Having the means and the abilities to exercise it at will but....chooses not to.