るところ

about to

→ 居る
phrase Common #2,467
about to Used after the plain nonpast form of a verb to mean that someone is just about to do something. Related forms include ているところ, meaning “in the middle of doing,” and たところ, meaning “just did.”
JA: これから夕食を食べるところです。
EN: I'm just about to eat dinner.

あなたの作文いくつか間違ってるところがあります

There are a few mistakes in your composition.

タバコ吸ってるところ親に見つかった

My parents caught me smoking.