Set it as your Home Console ASAP. This will allow you to access your games if you lose connection to the web.

Clear out the dashboard of as much as possible in the customise screen and only set up what you want on there. As Game Pass and the Store are available from pressing the Xbox button, those are two things you have quicker access to from there instead of the dashboard.

When pulling a menu up and you want to get to the bottom of it quickly, press RT and you'll drop down there. Some menus have a help section at the bottom and it goes to one space above that.

Wishlist games you're interested in and you can see how many of them are on sale easily.

Hover over a game you have and click the Menu (three lines) button. Go to Manage Game & Add Ons. On the left hand side of the screen, some games have Compatibility Options that you can click. This is where you find improved frame rates and the like as an optional thing to turn on.

Have fun, and welcome to the family.