Defining the space between section number and section title

Question

I am trying to define the spacing between the section name and section title in latex to get something like this . How can I do it?

Also how can I define the margin and all at the first page to get the margin of the title of the paper from the top followed by the authors like this.

Answer 1

The distance is defined (in the standard classes and so those that load them) by \@seccntformat, whose usual definition is

\newcommand{\@seccntformat}[1]{\csname the#1\endcsname\quad}

So the space is a quad (1em) in the current font. If you want a normal interword space, put the following magic in your preamble:

\makeatletter % access to internal commands
\renewcommand{\@seccntformat}[1]{\csname the#1\endcsname\ }
\makeatother