The only remedy to having too little space on your device is to identify and remove unwanted data - however, some might be difficult to identify.
Details about your storage capacity and usage can be found here:
Settings > General > iPad Storage
Here you will see the relative usage of different categories of data locally stored on the iPad. For example (looking from the right), the largest light-grey bar is empty/free space, then you’ll see a darker-grey bar corresponding with “other”, then a green bar for “Messages” and so on.
You may find these help pages offer some useful information and insight:
How to check the storage on your iPhone, iPad and iPod touch – Apple Support
About storage on your device and in iCloud – Apple Support
If, when looking at your own data storage usage, you see that the “other” category is consuming an disproportionate amount of space on your iPad, this support page may be helpful to you:
Clear Other storage on your iPhone or iPad - Apple Support
I hope this information and guidance proves to be helpful in resolving the issue.
