I have offloaded all the apps on my iPad and paid for more storage on iCloud and my iPad is still saying insufficient storage, what do I need to do, I can’t even use it?

Buying more iCloud storage does NOT increase the physical storage on your iPad. All you get by increasing iCloud is more space to sync more data with the cloud if the free 5GB of storage in the cloud is not enough. There is no way to increase the physical memory on your iPad.

I would be willing to bet your "Other" is taking up a lot of space on your iPad, meaning you have some corrupt data on the device. Go to Settings > General > iPad Storage and see what is taking up the most space. If, as I suspect, other is abnormally large, backup your iPad to either iCloud or iTunes on your home computer, then restore the iPad from your backup. See this link --> Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

What kind/model iPad do you own and what iOS is it currently running?

What is the “A” model number of your iPad?

The “A” model number of your iPad can be found on the lower area of the aluminium back of your iPad in small print letters right underneath the large, bold printed” iPad”.

Also, what is the storage rating of your iPad model?