如果你想表达自己不是很忙，你可以说:

I'm not very busy.
I'm not swamped with work.
I'm not overwhelmed.
I have some free time.
I have a pttle bit of time on my hands.

例如:

A: "Do you have time to meet up this afternoon?"
B: "Sure, I'm not very busy today. What time works for you?"

或者:

A: "How's work been lately?"
B: "It's been pretty good. I'm not swamped with work pke I usually am."