"We are not angry now."
Translation:No estamos enojadas ahora.
The negation precedes the verb Estamos.
Most certainly not. Somos is the we-form is the verb ser, estamos is the we-form of the verb estar. Two different verbs, which both happen to be translated as 'to be'.
You can remember when to use Ser with 'e-Doctor': Event, Description, Occupation, Characteristic, Time, Origin, Relationship. You can remember when to use Estar with 'Places': Position, Location, Action, Condition, Emotion, State.
In this case, we are not angry NOW. This is our current state - and also anger is an emotion. We have to used Estar.
Yes. Enojado is an adjective and adjectives agree in gender and number with the noun they modify. For example: Él no está enojado ahora - He is not angry now. Ella no está enojada ahora - She is not angry now. Ellos no están enojados ahora - They (a group of men or a mixed group of men and women) are not angry now. Ellas no están enojadas ahora - They (a group of women) are not angry now.