The 3D View can be found via the Windows menu. The keyboard shortcut is Shift+F1

3D View may be open already in a tab. Look for the matching tab name.

Change active camera in the Scene with the 3D view > camera selector. There is always a default Camera 1

Render: Activate render passes. Each render pass draws one type of thing the camera might see in the 3D view. They can be set to Never, Sometimes, or Always.

Copy to Scene: Makes a copy of the active camera and adds it to the root of the Scene. Here a camera has been added and renamed by the user.