You get 2-nd option of all main scenes by beating night 5.
Freddy movement can be tracked on cameras ( default pattern: 1A -> 7 -> 1B -> 5 -> 3 -> 6 ) or by sound cues - her laugh. She become a threat around 4 am after moving into last position. Here she will repeatedly attack from the right side. You cant see her at the door directly, so best strategy is periodically close the door every 5-10 sec and ALWAYS when you flip up the camera.
You cant keep Golden Freddy scene like the others, however it can be triggered at any time by typing: 6/9/6/9 in the custom night menu.