Hey CF. I just did my first paint correction last weekend. It's not something people can tell you how to do in a single answer. I read the PAC website (the sister site to this forum), countless threads here, watched Meguiars videos on youtube... the results were pleasing but not perfect. But scan through this forum (machine polishing) and/or search for "105" and you'll find tons of good info. I liked the youtube because you can see how fast the guy went, how long he stayed on a spot, how big of an area to do etc.
I'm not sure Harbor Freight really saves you money. A lot of that stuff breaks on the 2nd or third use. I got a great polishing kit here (PAC) for 219. Porter cable polisher, 105 and 205, pads, backing plate. I expect that to last me a long long time.
Good luck!