ipad storage full warning

The warning that you see likely does not relate to your iPad internal storage.

As described, you have perhaps exceeded your iCloud storage allocation - and it is this that you are seeing warnings with an invitation to subscribe to a higher storage tier.

All AppleID accounts have an initial “free” 5GB of iCloud storage - this being sufficient for basic iCloud synchronisation. If using iCloud for backup purposes, or file storage, you will very likely exceed your free storage quota - and may need to consider subscribing to the higher “paid” tiers of 50GB, 200GB and 1TB.

More details can be found here:

Upgrade to iCloud+ - Apple Support

Go to Settings > General > iPad Storage

What does it show exactly there?

nothing is wrong. ipad storage is the device storage & icloud storage is icloud stoage.

Please answer the question I asked above. Exactly how much storage is left out of exactly how much total storage on the device in GB (not percentage).