Hi aditib29,
Welcome to the Apple Community:
We are all Apple users here, like yourself, so have no access to your account or details.
You may need to ensure you have enough free space for the update to download:
(If you don't have enough space, then you would need to use a computer for the update !)
There's a discussion thread with more info:
You might want to check the list of things needed for updating smoothly, before you update you iOS.
https://discussions.apple.com/thread/253085233
Apple support have articles online (links below) to help you.
Update your iPhone, iPad, or iPod touch:
See these instructions, and more, in the article:
- Plug your device into power and connect to the internet with Wi-Fi.
- Go to Settings > General, then tap Software Update.
- If you see two software update options available, choose the one that you want to install.
- Tap Install Now. If you see Download and Install instead, tap it to download the update,
enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.
https://support.apple.com/en-us/HT204204
If your iPhone, iPad or iPod touch won’t update
https://support.apple.com/en-us/HT201435
Hope this helps you update more simply and smoothly :-)