You can enable live events from your Account Features page. Live streaming, when used properly, is an excellent tactic to engage your users and increase watch time.
After completion of the event, you’ll still be able to feature the recorded video in your channel’s playlists. There are a number of technical considerations when starting a live stream, so be sure to read the below resources well ahead of time. Also, be sure to check out YouTube's Streaming Guidelines and Troubleshooting Help Page for additional information.