Archived Where Does It Go?

If I archive my projects how long will they remain in the archived folder for me to refer back to? Is there a way to export more then one note at a time and still create separate notes in one note?

Archived projects will forever stay where they are until you decide to bin them (just like regular projects).

Is there a way to export more then one note at a time

You can shift or command select notes and choose File > Export

and still create separate notes in one note?

This I’m not sure I follow, perhaps you can describe better what you try to achieve?