1. Most android TV boxes use an HDMI video interface to play video and sound to a TV. Connecting the HDMI cable to a TV, powering up the box, and having the TV set to the correct HDMI input is all that is required.
2. Connecting to WiFi or Ethernet The interface can differ between Android TV box manufacturers, but an internet connection is needed to stream online content. The best setup is to use a wired Ethernet cable if possible, but not everyone will have a cable close and have to use WiFi. Most android boxes will have the wireless and Ethernet in Settings->Network->WiFi.
3. Once an internet connection is set up Kodi or other apps are ready to be used.