6 ft
The green light on the traffic light is on the bottom. The yellow is in middle, the red is on top. However, in some municipalities, the traffic lights are not vertical, they are horizontal. In these instances, the green light is usually, but not always, the furthest to the right.
A traffic light you seen change to green
a fresh green light is when the traffic light has just turned from red to green
It is usually on the bottom of the traffic light.
The lowest light on a traffic signal is green. Some cities use traffic lights that are not arranges top to bottom but rather side to side. In this event the green light is usually the furthest to the right.
'Go'.
Yellow light
On a vertical display traffic signal the green light is on the bottom. On a horizontal display traffic signal it is to the right, but may depend on that state (or municipality's) practice.
Fresh green light
bottom
Depends. If the light has a sign next to it that says 'Yield on green light' it means you can go when the light is green and there is no traffic coming from the opposite direction that could hit you. If there is no sign wait for the arrow.
There is no specific length of time for a red light. Traffic engineers make that determination according to the flow of traffic.