Lightroom Classic and using iPad Pro Lightoom version

Another thing to keep in mind is that you won’t immediately see all of your images on the iPad, because Lightroom Classic cloud-syncs only the images you have marked for syncing, and all synced images have to be from the same catalog. So to edit on the go, you have to do a little advance planning and first sync specific images to Lightroom Photos in the cloud. After those are uploaded, you can then edit them using Lightroom on iPad, and the edits will sync back down to Lightroom Classic.

Do you have an iPhone or Android smartphone?  If so, you can try it right now without the iPad.  In LrC, you need to create a collection, set it to sync with Lightroom and add some images to it.  On your phone, download the Lightroom app, sign in with your Adobe ID and you'll see those collections with your images in them.  Edits in the mobile app will sync and show up in LrC and vice versa.  The iPad workflow is the same, just with a bigger screen.
Have a look at this video for a more detailed walk through - https://www.youtube.com/watch?v=LLbgBs5IZgg&t=199s

Yes, you can do that. Lightroom Classic can sync photos to the cloud that you can then edit in Lightroom mobile. These edits do sync back. The only caveat is that Lightroom Classic does not sync up the original file, but a smart preview. That is good enough for most purposes, but it does mean that you cannot really judge noise and sharpening. The advantage of this system is that smart previews do not count in your cloud allocation, so you can sync up as many photos as you want and you won't run out of online space.