This is the problem with base model, lowest internal data storage Apple model devices.
A 32 GBs storage iPad starts out with approx 30 GBs.,after initial internal flash drive formatting.
Minus approx. 6.5 GBs for iOS/iPadOS leaves between 23-24 GBs.
Minus 3-6GBs, for iOS/iPadOS system operational reserve, that MUST BE MAINTAINED AT ALL TIMES, to ensure/insure normal, expected operation of iOS/iPad OS, leaves approx. between 18-20 GBs of actual, usable data storage space.
Even with 20 GBs of actual, usable internal data storage space in an Apple iOS/iPadOS device,
a 32 GBs data storage devices are, now, more quickly, becoming the “new” low storage 16 GBs internal data storage space devices, today, a 32 GBs Apple iOS/iPadOS device has 3-4 times the internal data storage space of older base model, low internal data storage,16 GBs. internal data storage Apple iOS/iPadOS devices.
In reality and in use, in 2021, a 32 GBs internal data storage device is kind of a joke and of limited usefulness, when up to 2TB of internal data storage ( approx. 1.8 TBs or usable internal data storage ) portable tablet devices exist today.
Purchasing a low storage Apple device, to save on the cost of the device, is a false economy.
The situation will ONLY get worse as the file sizes of iPadOS keep getting larger and larger.
All that stated,
Your iPad is probably close to being comoletely full of data.
You never, EVER completely fill up ANY computer or computing device full of data. EVER!
If you need to free up free, internal data storage space on an iPad/iDevice, you need to start by backing up your iPad to either Apple's iCloud ( you may need to pay for additional, monthly storage space ) or by connecting your iDevice to a computer running the latest iTunes or, if a newer Mac with a much newer macOS, use the macOS Finder to do the device backup and/or some other offsite, “cloud” data storage/backup services, like Google Drive/Photos, BOX, DropBox, Amazon Cloud Drive, Flickr ( for photos/images ), etc.
Then, delete any installed apps that you no longer use or use infrequently enough that they aren't missed (you can always reinstalled any purchased or free apps at some time later, as you need them).
In addition, uninstall any games that appear to be using a sizable chunk of your iPad's internal storage, as well!
Then, thin out/delete any music/videos/movies/TV shows/podcasts/screen recordings/photos-images/eBooks/
eMagazine/iBooks/audio books/Documents/PDFs, etc.
If you use a POP email account on your iPad, delete/thin out any old saved emails that maybe saved to your iPad.
To permanently delete photos/images off of your iDevice go into the Photos app and find the Recently Deleted folder/album and permanently delete any photos/images stored in that folder/album.
Also, you can check to see what other stuff is eating up all your valuable data storage space by going into the Settings App,,General Settings Panel, in the right hand column, tap Storage & iCloud usage panel ( in iOS 11 and later, it’s now called iPad Storage ), in the top Storage Panel, tap the Manage Storage panel, wait for a list of apps to generate that will tell you how much space each app is taking up on your iDevice.
Then, for older iPad models with a Home button, do a hard reset of your iPad by holding down both the Home and sleep/wake buttons simultaneously until your iPad goes to black and restarts with Apple logo, then release the buttons.
ALL iOS/iPadOS devices need to maintain, at the very least, a minimum of between 3-6 GBs of free data storage space, AT ALL TIMES, to insure normal/nominal functionalities/operation and general overall performance of any iOS device running iOS/iPadOS.
Good Luck to You!