removed new device by mistake when setting up

Have you tried resetting your password?

Apple ID Password Change.   -   

 What to do after you change your Apple ID or password - Apple Support  -   I suggest doing this before you change your Apple ID or password.

If you can't reset the Apple ID (iCloud) password, enter the Apple (iCloud) ID, and click Forgot Password. See if you can get a Rescue or Notification email option if necessary. Link to contact Apple Support at the end of the 2nd article.

Apple ID - Manage  -     

Apple ID – Forgot Password  *      

If you can sign into your Apple ID on the iPad, see if the 'Add a device to the list' section in the article below helps.

Apple ID device list -Check to see where you‘re signed in.   

If you can't sign into your Apple ID, what happens when you try? Error message(s)?