Setting up an exam shouldn't be a problem if you follow the right steps.
Here, we'll be guiding you on how you can setup your exam with ease, when logged in as an admin, click on CBT, you will see something similar to the first image you're seeing on this page.
the second image shows you the list of actions to be taken as an admin. Click on any of them depending on the kind of action you wish to take and fill in the form accordingly.