were is changing port on ipad

The iPad User Guide is an excellent source of information about using your iPad. Here is a direct link to the relevant page:

Charge the iPad battery - Apple Support

The Guide is a rich source of frequently overlooked information about your iPad and iPadOS. The Guide is available both online using a web browser (such as Safari), or as an Apple Books download:

iPad User Guide - Apple Support

https://books.apple.com/book/id1567104892

The Tips App, installed by default on all new models of iPad, provides a brief introduction - and leads you to the User Guide. In case you missed it, here is a link to the Tips App:

https://apps.apple.com/gb/app/tips/id1069509450

Apple also has a huge YouTube Channel - containing videos and feature guidance:

https://www.youtube.com/user/Apple

The charging/data port on an iPad is in the center of one of the short edges. On modern models, it is the only aperture that looks like a port of any sort.

Are you having trouble finding it?