I need to backup my phone files and photos

Hello ~ Go back through the article you came from and follow the directions here:

How to back up your iPhone, iPad, and iPod touch

What does iCloud back up? - Apple Support

~Katana-San~

You can follow the steps at the link below to backup your iPhone.

You can back up via iTunes (your computer) or iCloud (wireless)

How to back up your iPhone, iPad and iPod touch – Apple Support (UK)