\documentclass[twocolumn]{article}
\usepackage[top=3cm,right=2.85cm,bottom=2.5cm,left=2.5cm]{geometry}
\usepackage{fancyhdr}
\usepackage{picinpar,graphicx}
%حذف فرورفتگی اول پاراگراف
\setlength\parindent{0mm}
 
%برای اضافه کردن قسمت چکیده و کلمات کلیدی
\usepackage{cuted}
%بزرگ کردن حرف اول پاراگراف
\usepackage{lettrine}

\title{The Title of Paper}
\author{Author number1,Author number2}
%برای اینکه تاریخ نزند
\date{}

\let\AbstractBold\bfseries % dummy 
\renewenvironment{abstract}{%
       \strip
        \small
        \begin{center}%
          \AbstractBold\noindent\textbf{\Large Abstract}%
        \end{center}%
        \quotation}
        {\endquotation\endstrip}
\newenvironment{keywords}{
\vskip 4mm
\strip
\AbstractBold\noindent\textbf{\large Keywords:}%
}{%

\endstrip
\vskip 1cm
}

\begin{document}
\maketitle
\begin{abstract}
\noindent Abstract..abstract..abstract abstract abstract abstract Abstract..abstract..abstract abstract abstract abstract Abstract..abstract..abstract abstract abstract abstract Abstract..abstract..abstract abstract abstract abstract Abstract..abstract..abstract abstract abstract abstract Abstract..abstract..abstract abstract abstract abstract Abstract..abstract..abstract abstract abstract abstract Abstract..abstract..abstract abstract abstract abstract.
\end{abstract}

\begin{keywords}
\centering
keyword, keyword, keyword,keyword, keyword.
\end{keywords}
\section{Introduction}
\lettrine[lraise=0.2,lines=1]{\textbf{I}}{ }t is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. 

It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. 

\section{second}
It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. 

It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. It is a test. 
\end{document}