\documentclass{article}
\usepackage{amsthm}

\theoremstyle{plain}
\newtheorem{thm}{Theorem}[section]
\newtheorem{prp}[thm]{Proposition}
\newtheorem{lemma}{Lemma}

\begin{document}

\begin{thm}[description of theorem abc \cite{abc}]
  My theorem goes here.
\end{thm}

\begin{prp}[pleaze spelll check]
  My proposition goes here.
\end{prp}

\begin{lemma}
  A lemma here.
\end{lemma}

\begin{proof}[Proof of theorem abc]
    Proof goes here.
\end{proof}

\end{document}