There was an error connecting to iCloud
This means you don't have an active internet connection to access iCloud. From the picture, I can see you're not connected to WiFi but using a cellular network. To access iCloud and it's relative Settings you need to make sure:


Mobile Data is on
You have enabled Mobile Data for Settings


To enable Mobile Data:


Go to Settings
Mobile Data
Toggle the switch at the top


To turn on Mobile Data for Settings:


Go to Settings
Mobile Data
Go to Settings and toggle the switch so it is green