I'll be as prim as I can and not get into any scrapes, if I can help it.

我会尽量板着面孔，不去闯祸，如果我能做到的话。

Don't worry about me. I'll be as prim as I can and not get into any scrapes, if I can help it.

别担心，我会好好表现的，我尽量不给你惹麻烦就行了。