Is there a way to 'fly' through a scene in Blender with the mouse, like in Unreal Engine? That is, without animating the camera?
Blender supports two different navigation modes. To switch between them, edit preferences, go to the Navigation Tab where you'll find the "Fly&Walk" panel. select "Fly".
Depending on whether you have auto-save enabled for preferences, you may need to press the "Save Preferences" button to make the change permanent.