Translation:We are on the eighth floor.
层 is a measure word and 楼 is a noun or a measure word.
I'm on the fifth floor = 我在五楼 (5th floor is a place/noun)
My house has five floors = 我的家有五层(楼). (5 floors is a count/measure)
In google translate if you put 五楼 it treats it as a noun (fifth floor), but 五层 is treated as a count (five floors).