How to update my phone software. ?

VPN or proxy connections might prevent your device from contacting the update servers.

• Get help with over-the-air iOS updates - Apple Support
• Remove and download the iOS update again

If you still can't install the latest version of iOS, try downloading the update again:

1. Go to Settings > General > [Device name] Storage.
2. Find the iOS update in the list of apps.
3. Tap the iOS update, then tap Delete Update.
4. Go to Settings > General > Software Update and download the latest iOS update.

If you don’t see the update in the list of apps or if the issue happens again, you need to update your device with iTunes.

Try updating iOS after each step.

• Try Forget the WiFi network and add again
• Try another WiFi network 
• Toggle set automatically off and then on
• Reset your network settings
• Force restart your device
• Remove any beta profiles, if applicable
• If everything fails:- Use iTunes or Finder (for macOS Catalina+) to update your device instead of over-the-air

• Get help with iOS update and restore errors - Apple Support
• If you see an error when you update or restore your iPhone, iPad

iOS / iPadOS devices cannot be hacked or infected with Virus / Malware / Spyware if it is updated to latest iOS/iPadOS, unless you have intentionally downloaded spurious softwares or unauthorised apps directly from internet and installed on your device or/and have Jail Broken. 

It (Hacking) also depends on how careful are you in sharing sensitive and valuable informations of your iPhone such as Passcode, Password etc with your friends and family members.