\documentclass{article}

\begin{document}

  \paragraph{AAA}

  Aaa


  \paragraph{BBB}

  \leavevmode\par\noindent Bbb


  \paragraph{CCC}\hspace{-1em}\footnote{fff}

  \noindent Ccc


  \paragraph{DDD}\hspace{-1em}\footnote{fff}

  \leavevmode\par\noindent Ddd

\end{document}
