How to download photos from my phone?

There are several options in this article→Copying personal photos and videos from iPhone, iPad, or iPod touch to your computer

To download (or actually upload) photos to iCloud open Settings, tap on your name at the top, then tap on iCloud and turn on the switch for Photos. Then just wait, preferably with the phone plugged in and connected to Wi-Fi (unless you have a 5G-enabled phone).

Note that iCloud syncs photos; it doesn’t archive them, so you can’t delete them from your phone without the photos also being deleted from iCloud.

If you want an archive in a cloud so you can delete them from your phone you can use Google Photos, Amazon Photos, Shutterfly, Dropbox, box.com or a number of other cloud services. Google Photos is the most convenient; just install the free Google Photos app on your phone, log in to your Google account, and your photos will sync to Google Photos as if by magic.