Assume functor $ F:C \rightarrow D$ where $ C$ is a small category and $ D$ is cocomplete category. Now let $ S$ denote a functor given by composition $ D \xrightarrow{\text{Yoneda embedding}}D^* \xrightarrow F^{*} C^*$ ($ C^*$ is a category of presheaves from $ C$ ). Prove that $ S$ has left adjoint functor.

The problem here that I don’t know where to start. So I need a hint to begin with. Thanks!