How to position drop down menus?

Question

css

Hello,
I'm adapting the template for myself, here
I downloaded the template here
, but there is a non-drop-down menu, but I really need drop-down menus. Somehow googled, and now the submenu drops out, but not exactly under the main item (in particular, "About us"). How to make it drop out exactly under the menu item on which the cursor was hovered and orient the dropped items to the left?
Here is the pen menu

Answer 1

https://codepen.io/LenskyUser/pen/YQzEaL seems to be like this