Keep getting error of not connected to internet when trying update and my phone is connected tried multiple wifi enabled locations( work and home etc) battery fully charged! How can I fix this?

You need about 7 GB device storage and good Service & Wi-Fi.

and my phone is connected tried multiple wifi enabled locations( work and home etc)

If you are connected to work Wi-Fi network, that mean you are using Public Wi-Fi, see this Apple article: Use captive Wi-Fi networks on your iPhone, iPad or iPod touch

Use captive Wi-Fi networks on your iPhone, iPad or iPod touch – Apple Support (UK)

If they are On, turn Off Hotspot & VPN.

Go to: Settings -> General -> Software Update.

See the following Apple articles:

Update your iPhone, iPad, or iPod touch

Update your iPhone, iPad, or iPod touch - Apple Support (IN)

If your iPhone, iPad or iPod touch won’t update

If your iPhone, iPad, or iPod touch won't update - Apple Support

You can do the update via PC, see this Apple article: Update software on iPhone, iPad or iPod touch in iTunes on PC

Update software on iPhone, iPad or iPod touch in iTunes on PC – Apple Support (UK)

If you have a Mac see this Apple article: Update your iPhone, iPad, or iPod touch with the Finder

Update your iPhone, iPad, or iPod touch with the Finder - Apple Support