How do I transfer my iCloud to Verizon iCloud?

Verizon doesn’t have an iCloud, only Apple.

Verizon does have their own cloud services—cloud, not iCloud—and I would suggest discussing any migration from Apple iCloud to Verizon with Verizon representatives.

Verizon does have an app for this, and I’d take a careful look at the restrictions and limitations (see below) before transitioning.

The app: https://apps.apple.com/us/app/verizon-cloud/id645682444

I don't think you can directly transfer data between two cloud drives.

You need to download them to a Hard Disk from one cloud drive and then upload them to another.