Verification code failure after multiple attempts
I have tried to verify my email address about 20 times now and each verification code fails even though it goes directly to my email address
iPad Pro 12.9-inch, 3rd Gen, Wi-Fi
Normally, if your e-mail address was associated with an ID in any way, for example as a Reachable at or Rescue e-mail address, then it can't be reused with another Apple ID for approximately one year. I have also seen posts that stated Apple told them there was a 30 day waiting period before the address could be used again. You will need to get another e-mail address to use as your Apple ID or you can try waiting 30 days to see if that works.
Do you have access to another WiFi network where you can try? That has worked for several people.
Try a restart.
Restart your iPhone, iPad, or iPod touch
Try a forced restart.