I checked out the sample site and I took a peek at the theme options, and it notes:
The Primary Menu is located to the right of your site title, and can be configured by going to Appearance -> Menus.
The information about how to do a custom menu is here:
Now, you've already started a custom menu, which is great! But you need one more step before we dive into that.
First, go to Pages > New Page:
*Create an About page, add any text you like, and save it.
Now, go to Appearance > Menus
*Scroll down until you see the Pages module on the left
*Save your menu
Now go back to your Pages (Dashboard > Pages > All Pages)
*Go to edit your CV page
*On the right side, you'll see Page Attributes
*Change "no parent" to "About" from the drop-down menu
You'll need to do this with your Bio page as well.
Once you do these steps, your custom menu will appear AND bio and cv pages will be nested under your About page!
I hope that helps!