One of the biggest questions asked was, how do I add my friends to a party to play together?
Before that, how do I even add my friends to my friends list?
While, through various testing, I have come to the conclusion that Communications -> Friends -> Add Friends is not working or implemented yet.
Instead, you have to add your friends through the XBox Console Companion Microsoft Store instead.
Once you have added your friends via the app, be sure to use the same credentials as you are using to test PSO2:NS, they will automatically show up on your PSO2:NGS friend list under the XBOX app list.