Stop in for a cup of coffee

Don't have a random. Do have a couple of 7" buffer/polishers. Never used them. Could practice on the wagoneer - nothing to loose there.
Just keep it on a 30* angle to the surface using only one side of the pad and keep it constantly moving so you don’t burn the paint. Better to move too fast than not fast enough.

Also, clean the pad regularly to keep the buffing compound and paint residue from building up. I always just used a flat head screwdriver presses slightly into the pad while running the buffer out in the open. Just work the screwdriver across the pad while running and it will knock off the debris and fluff the pad.