Hopefully by this point you have un-boxed your system, you will notice a few cords (Xbox One has a power converter Playstation does not.) The wall plug is obviously the power cord, the second is your HDMI cord this allows the game system to show up on your tv screen.
You will find two to three cable ports, finding which one is which is easy. The HDMI will go in the back of your tv.
Once hooked up your game system will need time to boot up. Wait a few hours before installing console data
You will need to create an account, here are a few videos on how to create accounts on Playstation4 and Xbox One.
After your account is created you can begin to install games. Insert the selected game into the game system, select the game and start it. A menu screen will show up asking to install the software. Click yes and wait.
Grab a controller and get playing!