Could you please save me a seat when you get to the theater? I will be late for five minutes.
你可以到電影院的時候幫我佔個位子嗎？我會遲到五分鐘。

補充：
「到達」 有以下兩種說法
1. get to xx：
⚠️到家：get home, (home前面不加介系詞。)

2. arrive in+ 大地方(城市/國家)
arrive at+ 小地方(場所)

When I got to the theater, Cherry had left.
= When I arrived at the theater, Cherry had left.
我到戲院的時候，切利已經離開了。