Deleting Vanilla Elements
You can hide all default/Vanilla elements (including some mod elements) that are visible in the layout editor. If they are visible, just right-click them and click on Delete.
Bringing Back Deleted Vanilla Elements
To make deleted/hidden Vanilla elements like buttons, logos or other types of elements visible again, just open the layout you deleted them in, then navigate to the menu bar -> Element -> Deleted Vanilla Elements and left-click the element(s) you want to make visible again.
If the deleted elements aren't listed in the menu, you have the wrong layout open and need to find the one you deleted them in.