When setting-up your iPad, you will need an AppleID account if you are to benefit from the many services that are available via iCloud.
You can use an iPad entirely standalone should you choose to do so, but you will forgo synchronising with - and backing-up your data to - iCloud. Without signing-in to iCloud, your data will only be stored on your iPad; if anything ever goes wrong, you’ll not be able to recover data (such as your Keychain - within which your Passwords are stored) from an online backup.
Don’t forget that your iPad is very likely Activation Locked to the AppleID with which it was previously activated. As such, after performing a reset, you will still require the associated AppleID credentials/account to satisfy the Activation Lock. Unless the Activation Lock can be cleared, you’ll be unable to reuse the iPad.