upload photos from USB to icloud

how do I upload photos from USB to icloud [?]

You didn't state which device you will be using, so I've presumed it to be a computer.

In one of two ways:

You can sync the files to iCloud - insert the USB drive into your Mac and when it is mounted drag and drop the image files from the USB drive into your iCloud Drive folder (or if you have it set up to sync your Documents folder or your desktop). If you have a Windows computer you can do the same thing - use File Explorer to place the file in your iCloud Drive folder.

If you have iCloud Photos set up to sync with iCloud you can import the photos into your Mac's Photos app (or drop them into the iCloud Photos folder on a PC) and they will sync to your iCloud account.

I'd suggest an iMac (being an iMac owner). 😉