how can i upgrade my iphone 5

The latest version of IOS for your Iphone 5 is iOS 10.3.4. You can not upgrade further than this as it is not supported.

For more information on IOS updates and to see how to upgrade if you haven't already - this article should give you some steps. Althought meant for IOS 13, it should still apply in most cases to your upgrade.

How to update to iOS 13 or iPadOS - Official Apple Support

If you are talking about upgrading your phone to a new phone - you can restore a backup and transfer it onto a new device.

Find out more information at the Help Article below

Transfer data from your previous iOS device to your new iPhone, iPad, or iPod touch - Apple Support

Otherwise, welcome to Apple Community Forums and if we can help with anything else, just let us know! :) Have a great day.

Assuming you are asking about iOS, you can't. The iPhone 5 doesn't support anything after iOS 10.