“Scared to rock the boat and make a mess”

Katy Perry – Roar Lyrics on LyricsMode
EXPLANATION
Scared to mess things up so she didn't say anything when she had a great idea.
EXPLANATION
In this set of lyric's she's saying that she's afraid to anything. Since, that the "you" is ordering her to do things, we can guess that she is afraid to upset "you" or just too scared to do anything that ruins whatever "you" planned.