2018 Factory Tow package
 

What else do I need to buy in order to tow stuff.. sorry..new to towing.. I got the tow package with the car from factory built

Depending on what you are towing, you may need a brake controller. Audi sells one manufactured by Curtis or there are other brands that may be used. If you choose a different brand, you then have to research how to connect it to the Audi provided controller connector under the dash.
you may or may not need a socket for plugging the trailer unbiblical into your Q7. It is a separate accessory and is not provided with the factory towing package.
Finally, you will probably need a ball mount and ball with an appropriate offset and ball size for whatever trailer you will be towing.
Bruce

thx for ur help

I meant to say “towing package” not “brake package” by the way. I’ve edited it in my original answer but...
Bruce

I am just towing a bicycle platform/rack that requires a 2 inch ball.. I just need a ball mount then? any recommendations?

This is a rack, not a trailer? If so you can simply pick a straight ball mount.
You can shop for the ball mount online at someplace like “etrailer” or Amazon or you could simply run to your nearest U-Haul dealer. They should have exactly what you need.
If you are pulling a bike trailer, things change. You need to know the height of the trailers ball socket, the part that drops onto the ball. Then you choose a ball mount with the correct offset to allow the trailer to be level when it is towed. This is usually explained in detail in the manual that comes with a trailer.
Bruce

If you are actually towing something, you will also need the electrical socket to plug into. That is not included with the "tow package". Some cars do come with it from the factory (it was an added orderable choice) but some did not have that option checked off. You can buy an OEM-equivalent cheaply from amazon.
There was a thread ~ 1 month ago that discussed that, so if you need to add it you can find some tips in that thread.

Go to Pep Boys or similar store and buy this. I spent a long time finding right one. Good Luck!

https://cimg4.ibsrv.net/gimg/www.aud...611855211a.jpg
https://cimg5.ibsrv.net/gimg/www.aud...e4a86c48a8.jpg

Good information although I find it pretty stupid that a towing package does not come with this installed! My much cheaper Honda Ridge did.....

Welcome to the new Audi. goes with the floor jack, cargo cover and other items that used to be included but now an option.