Event signup - email address verification?
You might want to consider using Caldera Form Wordpress plugin, then add the CIVICRM Caldera Form as well (https://github.com/mecachisenros/cf-civicrm).  This provides a more powerful way to register various forms with CIVICRM including events.  Though i have not done what you asked here on email verification as part of registration, i saw that Caldera has a free plugin with registration (Verify Email for Caldera Forms) which does what you mentioned.  I think it is worth a try.