re: Got an XbONE today - Any tips?

Killer instinct is free arcade fighter
go digital with games you know you will play for along time so you can take advantage of the voice feature allowing you to switch between any and all downloads
get forza
I've never tried the NFL app but if your a fan why not
when your in snap mode double tap the Xbox button on controller to switch between the two
if you get a party invite and miss it because your in the middle of the game go home and at the top is the notifications you missed and you can accept it from there