高手，您说的对，不仅细看，还挑出错了:))

steal away 有两解:

1. 偷走(某物)
Mary stole away your heart.
玛丽偷走了你的心。

2. 偷偷离去
He stole away without anyone seeing him.
他偷偷地走了, 谁也没有看到他。
"Steal away from bad company" here means to leave bad guys swiftly and silently like a thief might.
One should surround himself with good people.

So your understanding is right. Thanks :)