If you are wanting to walk a new employee through a basic training on how to approve, reject, and reassign items in Core iQ, it's best to start with a small campaign. Find a small list of customers/members in the platform and queue up a campaign to those individuals using the status of New. Make sure to assign the Sending Banker to be the employee you are training. This will queue a small number of items to that employee which you can use to train them on the three basic actions in Core iQ.
From there, it's as simple as either having them log into Core iQ or you can use the Impersonate This User feature on their Employee profile if you want to view their dashboard from Admin account. Either method will give you a view of the items that are queued in Core iQ for them, as well as their current permissions. You can then walk them through the basics of viewing a pending communication, approving or rejecting that communication, and viewing customer/member profiles in Core iQ. Just make sure to completely Remove all of the pending training items from your employee's queue. That way nothing goes out to a customer on accident!