To create a new managed Apple ID you will need access to an Apple device. Any Apple device will do. Once you create the account you can sign out of the device.
Open Settings and click sign in in the upper left.
Input your Benet email address.
Click Continue.
Do so if you want your the current apps on your iPad to be backed up to iCloud.
Once signed in you will see you now have 200GB of iCloud storage. If you do not want this Apple ID associated with this particular device, sign out.
The benet.org Apple ID should only be associated to Apple devices assigned to you by Apple or with websites where you will be expected to sign in with it.