Whow can backup my photos?

See this Apple support link—>Keep your photos safely stored and up to date on all of your devices - Apple Support

And also this one—>Transfer photos and videos from your iPhone, iPad, or iPod touch - Apple Support

If you don’t use either of the above photos will be included in your backups—>About backups for iPhone, iPad, and iPod touch - Apple Support. Note that if you DO sync photos to iCloud they will not be in the backup, as that would be redundant.

There are also many 3rd party options: Google Photos, Dropbox, Box.com, Shutterfly, etc.

Back them up where? Do you have a destination you'd like to back them up to?