*You must have the correct permissions to perform this task*
Users that are yet to verify their accounts are called 'Pending Users' and can be found in the App called such in your Site Settings area. The Site settings area gives access to the key administrative functions, such as managing Users and Teams amongst others. In addition to this, other things like Export and Import Summaries, as well as Site Assets (images, select lists etc...) are also located here.
In order to access this area, when on your site simply click on the Launchpad, followed by then clicking on the Cog. After doing this you, depending on your User Permissions you will be presented with what is displayed below:
In this instance you are interested in the Pending Users so it is this App that you should select. Doing this will present you with a List of your sites' un-verified users like seen below.