Password reset loop during iPad setup for a child

Trying to set up a new ipad. Had to change my password and got locked out so I sent it to Apple they sent email to allow me to do it. Now obviously it works because I had to use it to log into this site. But, when I use it on the new ipad it sends me a code, I enter it then I takes me back to sign in again. UGH!!! Very FRUSTRATING!!! Please help! I am attempting to setup a refurbished ipad for my grand daughter under "Set up for a child in My Family" that is the option I chose.

[Re-Titled by Moderator]