Hello David,
Welcome and thanks for joining.
You are in grave danger of kissing goodby to your Audi’s warranty on your one year old car, by attempting to service the car yourself.
I’m not sure if you own the car outright, or have it on something like a PCP, but whatever, the car will be deemed to have incomplete service history, and will be devalued accordingly.
Sorry to point out that if you don’t know what oil to use, then you are not in a good place to start anyway.
Adblue from Aldi’s? Same principle applies if you have to argue any warranty.
Kind regards,
Gareth.