arrive是不及物动词, 后面要跟介词in或at, 表示大城市或国家时用in, 表示小城市,乡村,车站等的小地方的时候用at.
例如:We arrived in Beijing yesterday.
My father arrived at the village last week.
注:如果后面接的是地点副词,则不加介词
例如:I arrived home at 9:00.
reach 是及物动词,后面不需要跟介词,可以直接跟地点。
例如:Amy reached Shanghai last night.
get 为不及物动词,后面常和介词to搭配使用, 但如果到达的地点为副词时,要把to去掉,直接加副词。
例如:Amy got to the station at noon.
My sister got here early in the morning.
注:如果到达的地点不明确,我们不能用get和reach, 只能用arrive.
例如:When we arrived, he wasn`t there.
总结:同样以到达上海为例,三者的区别:arrive in Shanghai, get to Shanghai, reach Shanghai,三者区别很小,主要是不要混淆了介词。