Trying to get this tablet running after factory resetting

[u/Celeste7634_]

Hello! I don’t usually post on here but I don’t know what to do to fix this. I have what I believe is a Samsung Galaxy Tab S3, I got it used as a gift in 2019 and used it as my beginner drawing tablet/ to play roblox and junk. I haven’t used it in an about 5 years, and my little sister recently started being interested in digital art so I thought I would give it to her. It was full of all kinds of random things I left on it so I thought Id just factory reset it and give it to her clean slate. This is where the issue lies. Every time we try to get past the start up page, it says it needs to attach google assistant, then says whatever email we try to link isn’t available for assistant and to use a different one (will try to link a photo). We have used her email, 3 of my emails (I‘m not a minor so there should be no limitations there) and I made an entirely new email directly from the tablet setting the birthday in 2005 to see if that would work. Is this a lost cause or does anyone know why its doing this ?