Menus Help!

Hello,

I am loving Agama Blue so far, but am having the hardest time changing the menu at the top. I would love to make a dropdown menu for sublinks, such as the ones you see on the 2nd picture on this page: https://help.pixpa.com/kb/root-level-top-level-links-and-sub-links/

Can anyone help me with this?

Thank you!
Fred