The easiest way to shut-down an iPad, regardless of model, is from iPad settings:
Settings > General > Shut Down
More information can be found in the iPad User Guide; here is direct link the the relevant page:
https://support.apple.com/guide/ipad/ipad63d30b5a/ipados
The iPad User 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 useful feature guidance:
https://www.youtube.com/user/Apple