Don't buy into all audis having hard paint, it just isn't true. So best practice is always recommended. Nothing worse than assuming its hard only to not realise you are actually instilling the marring yourself. Also, tread careful at the bottom of the wings. From me to you, paint often gets a lot thinner down there for some reason.
Using a random orbital its all about pressure, slow movements and level machine. I run one to one tuition and the most common mistakes are people not realising just how much pressure is required, and not realising that even a few millimetres off parallel and you significantly reduce your cut
Polishing is an art, not a science, but to generalise a work area is roughly 2ft by 2 ft. That doesn't mean you have to work in squares, if you stretch it one way you can shrink it the other to cover the same area
Spread most polishes at a speed of 2ish, in the middle of your work area, then up it to speed 5ish and work the extent of your area in north to south, then east to west directions.
Apply enough pressure to slow the machine to roughly 2 revolutions per second (use a sharpy line on the backing plate for a visual guide)
Make sure its the pressure that is slowing the machine, not you holding the machine crooked (the machine must be parallel to the panel you are working. As the machine curves, so must your machine to match)
Use plush microfibres to remove your residue, not some crappy t shirts like some still do lol
Start with your weakest combo, follow the above, if you don't get the desired results change one thing only! Either up the pad OR the polish, and try again. If that fails, up the other.
If this is your first venture into machining i genuinely recommend you start on a lesser vehicle or even a scrap panel. A lot is made of the safety of a random orbital machine, i know people who amaze me they can make a cup of tea properly and not need a trip to A&E. Point is its a power tool, and can cause damage to your pride and joy, always best to make mistakes elsewhere
Hopefully these guides will help. If you don't get what you need feel free to message me, it maybe something very specific you are doing wrong and small things can make all the difference sometimes