Epic Universe, the first major new theme park in the US in 20-plus years, is opening in Orlando, Florida, on Thursday.

Epic Universe represents the largest investment Comcast has made in Universal’s theme parks since gaining control of the business in 2011.

The theme park, which officially opened to the public Thursday (it has been hosting paid previews for a couple months), boasts four immersive themed lands surrounding a central green area called Cele...