https://www.cnet.com/news/spacex-falcon-heavys-historic-first-commercial-launch-how-to-watch/

SpaceX will have the official livestream on their website, as well as at the YouTube Live link below, 20 minutes before launch:

As with the first launch of the Falcon Heavy, SpaceX will try to safely land the two side rocket boosters back at Cape Canaveral Landing Zones 1 and 2 in Florida.