Help me

Hi Arfan_90,

If you visit an Apple Store, that will likely let you use their wi-fi.

Or you can use a computer .... if none available ... can you borrow a friend's computer ?

Apple support have an article online to guide you :-)

Learn how to update your device manually 

if you're using a Mac with macOS Catalina or later,

or 

if you're using a Mac with macOS Mojave or earlier or a Windows PC.

See the complete article:

Update your iPhone, iPad, or iPod touch - Apple Support

All the best.