There are the f and ctrl (or command) f keyboard shortcuts for re-setting the zoom and so forth.
See:
https://carbide3d.com/carbidecreate/shortcuts
and
As noted, there is a Layers palette which will allow controlling layers and the objects on them, but for a given layer, it’s object creation order, and newer objects will be superimposed on older ones and may need to be shifted out of the way to access the lower objects.