I'm slightly befuddled by is what it means when I'm asked to

$\textit{Draw the Feynman diagram in momentum space for the two point function of}$ $\frac{\lambda}{3!}\phi^3$ $\textit{theory for order}$ $ O(\lambda^2).$

I can draw Feynman diagrams, and I thought two-point function meant

$\langle0\|\phi(x)\phi(y)\|0\rangle$

and what I know about $ O(\lambda^2)$ is that it will have more diagrams than $ O(\lambda).$

Other than that, I'm a bit lost. I mean, I'm not even sure if this is a really simple calculation or quite a long one.

Apologies to myself if anything I've written above is embarrassing.

I'm slightly befuddled by is what it means when I'm asked to

Draw the Feynman diagram in momentum space for the two point function of $\frac{\lambda}{3!}\phi^3$ theory for order $O(\lambda^2).$

I can draw Feynman diagrams, and I thought two-point function meant

$$\langle0\|\phi(x)\phi(y)\|0\rangle$$

and what I know about $ O(\lambda^2)$ is that it will have more diagrams than $ O(\lambda).$

Other than that, I'm a bit lost. I mean, I'm not even sure if this is a really simple calculation or quite a long one.

Apologies to myself if anything I've written above is embarrassing.