how do I download my messages from iCloud?

As per this article Use Messages in iCloud - Apple Support

You can use Messages in iCloud on your iPhone, iPad, iPod touch, Apple Watch, and Mac. For your privacy, Messages in iCloud is end-to-end encrypted,* which means you can't view or access Messages online via browser. 

So messages can't be downloaded from iCloud.com

how do i get my message back if i deleted it