Existence of a left adjoint to the functor between cocomplete category and category of presheaves on small category.

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!