Here's the info from a Google article on setting up live streaming on YouTube.
"First things first, you'll need to enable Live for your channel.
Confirm that your channel is verified and in good standing.
Then, enable live streaming from Creator Studio tools --> Live Streaming.
Once enabled, you have two options to start live streaming on YouTube.
•We have an easy, instant way to start streaming now. Start sending content - we'll automatically start and stop the stream for you.
•You can also schedule a live event. Preview before going live, change privacy settings, setup a backup for redundancy and manually start & stop."