Can't see added cube on my scene collection When I select add and then cylinder, cube or whatever, then I can't see the cube on my collection side menu on the right.



I want to do some booleans from the air intake seen in screenshot 2.
That's why I need to be able to select the cube and the object I'm modeling.
But if I can't select the cube, I can't do it that way.
If you add an object in edit mode, that object will be part of the active object. 

To make individual objects exit edit mode and add the new objects in object mode.

Read: Why can&#39;t objects in Edit Mode have their own name?