1. I need to set an indent which must be equal to 1.27 cm, but, actually, I have no indent at the first line after title. How can I add it at the beginning of EVERY LINE, including the first one?

2. Font of headlines must have bold type with size 16. Besides, line-to-line spacing must be 1.5 everywhere. Instead of it, I have very large line-to-line spacing between any text and headlines by default

Here is my preamble:

\documentclass[a4paper,14pt ]{report}
\usepackage[T2A]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{amssymb,amsfonts,amsmath,mathtext,cite,enumerate,float}
\usepackage{graphicx}
\usepackage[14pt]{extsizes}
\usepackage{times}
\usepackage{hyperref}
\usepackage{tikz}
\usepackage[labelsep=period]{caption}
\usepackage{parallel,enumitem}
\usepackage{tabularx}
\DeclareCaptionLabelSeparator{par}{\par}
\captionsetup{labelsep=par,justification=centering}
\graphicspath{{images/}}

\newcommand\tablecaption[1]{
\captionsetup{labelsep=par,justification=centering}
\caption{#1}
}

\renewcommand{\baselinestretch}{1.5}\normalsize
\makeatletter
\renewcommand{\@biblabel}[1]{#1.}
\makeatother

\usepackage{geometry}
\geometry{left=3cm}
\geometry{right=1cm}
\geometry{top=2cm}
\geometry{bottom=2cm}

\renewcommand{\theenumi}{\arabic{enumi}}
\renewcommand{\labelenumi}{\arabic{enumi}}
\renewcommand{\theenumii}{.\arabic{enumii}}
\renewcommand{\labelenumii}{\arabic{enumi}.\arabic{enumii}.}
\renewcommand{\theenumiii}{.\arabic{enumiii}}
\renewcommand{\labelenumiii}{\arabic{enumi}.\arabic{enumii}.\arabic{enumiii}.}
\renewcommand{\rmdefault}{ftm}


Why is there a very big indent?

As for the indent, I want to fix this problem:

-
It's a good practise to ask separate. To 1.) usepackage{indentfirst} -- 2.) Depends on the document class. Please provide a MWE. –  Marco Daniel May 19 '12 at 12:15
"Why is there a very big indent?" Do you mean the gap between the headlines? That would even be a third question and one impossible to answer without a MWE. –  Christian May 29 '12 at 16:25

I need to set an indent which must be equal to 1.27 cm, but, actually, I have no indent at the first line after title. How can I add it at the beginning of EVERY LINE, including the first one?

The KOMAscript bundle has an environment called »addmargin«. If you use a KOMAscript class (scr-book/reprt/artcl), you got it already, otherwise load the package scrextend.

The code is:

\begin{addmargin}[1.27cm]{0pt}
Your text t t t t . . .

The OP was missing the "indent at the first line after title" (heading?), so I'd rather think \indent Some text or \usepackage{indentfirst} is the solution. –  lockstep May 19 '12 at 12:29