I need it because I believe that was the one that was setup on it
Also if someone else is accessing my ipad without my permission how can I get them to stop cause they are the ones who set it up without my knowledge
If someone else set up your iPad using their Apple Account, it will be locked to them with their Apple ID/Password, which will not be completely shown to you.
As for finding your Apple ID, that would be one you should know as it is an email address that would have been used by you. Apple provides some tips for finding a previous Apple ID email address, but there is no lookup by device that will show you what that is.
If you forgot your Apple Account primary email address or phone number - Apple Support
If you have an Apple Account signed into your device and it is locked or cannot remove it, then you will have to provide proof of ownership of that device and it can be reset, while also wiping all the data from the device. In most cases the proof of ownership will be the original purchase receipt from Apple or Authorized Apple Seller, as Apple does not get involved in any third party sales.
https://al-support.apple.com/#/al/agreement
Once the device is wiped, set the device up with your Apple Account. If you think someone else may know the Password to that account then you will also want to change your Password. Also set the Passcode to one that is not easily guessed such as "1111". Then your device is secured and no one else will have access.
If someone else set up your iPad using their Apple Account, it will be locked to them with their Apple ID/Password, which will not be completely shown to you.
As for finding your Apple ID, that would be one you should know as it is an email address that would have been used by you. Apple provides some tips for finding a previous Apple ID email address, but there is no lookup by device that will show you what that is.
If you forgot your Apple Account primary email address or phone number - Apple Support
If you have an Apple Account signed into your device and it is locked or cannot remove it, then you will have to provide proof of ownership of that device and it can be reset, while also wiping all the data from the device. In most cases the proof of ownership will be the original purchase receipt from Apple or Authorized Apple Seller, as Apple does not get involved in any third party sales.
https://al-support.apple.com/#/al/agreement
Once the device is wiped, set the device up with your Apple Account. If you think someone else may know the Password to that account then you will also want to change your Password. Also set the Passcode to one that is not easily guessed such as "1111". Then your device is secured and no one else will have access.
I don't remember my apple id when I set up my iPad again after being unlocked
