I want to upgrade microsoft stream to create live events

Hi, going on the documentation, the live events feature in Microsoft Stream requires an https://docs.microsoft.com/en-us/stream/live-encoder-setup, which is extra and not included.  The simplest option is using Microsoft Teams:

“Plug in your laptop and go...

Produce the live event using Teams, a lightweight option to create the event and invite presenters and panelists to participate on their own devices“

These options are compared https://docs.microsoft.com/en-us/stream/live-event-m365.  

The licensing and requirements is covered here - https://support.office.com/en-gb/article/get-started-with-microsoft-teams-live-events-d077fec2-a058-483e-9ab5-1494afda578a.  Who can watch live events is mentioned https://docs.microsoft.com/en-us/microsoftteams/teams-live-events/plan-for-teams-live-events#who-can-watch-live-events.

Hope some of that helps.