\documentclass{report}

\usepackage{enumerate}

\begin{document}


\begin{enumerate}
   \item Yes I am a Mother Nature Son\\
   \begin{enumerate}[I]
      \item And I’m the only one
      \item I do what I want
   \end{enumerate}
   \item And I want what I see\\
   \begin{enumerate}[2.a.]
      \item Could only happen to me
      \item I'm so freeeeee
   \end{enumerate}
\end{enumerate}

\end{document}