Hi, OK here are next steps. After you purchase your receiver you will want to setup your room and speakers properly. This is often determined by things we can't control like the size of your room, family considerations, neighbors if you live in an apt, etc. I have two diagrams posted in my thread on ceiling treatments that lay it out.
To set up the seating and speakers properly I used a tape measure and a laser pointer.
Once you have your room setup and your new receiver installed run the audyssey program that comes with it. There is a microphone included and a setup wizard that walks you through it, very easy. Once you get that far see how you like it and THEN we can discuss room treatments.
Now, the new Audyssey app can be installed to your PC from the microsoft store. The calibrated mike can be purchased on amaxon. Those are the last things to consider after you do everything else. So, if you want help setting up your room please list the speakers you have and post some pics of your room. You can download the manual for your receiver from the Denon website today, probably a good place to start, OK?