Hello Nicole,
Thanks for submitting a question about creating a drop-down menu. Yes, you are correct that in order for drop-down effect to appear, you can add the desired pages as “children.”
We have a full guide regarding how you can disable a top menu item link. Basically, you will be editing the menu in the customizer and adjusting the pages so that they display under the top-level item, and thus you will not see it appearing in the menu itself, it will be nested underneath the parent page.
Best,
Christopher M.