In the LaTeX mode of Emacs there is a nice feature for environments.
Instead of repeating once and again
\begin{<environment>} \end{<environment>},
use the command
C-c C-o <environment>
In the case of basic environments this option will ask you some details of the format. Example, for tabular it’ll ask you the columns format, for minipage will ask you the width of the minipage.
[...] you choose to try emacs yourself, I recommend to check some old post of mine, about an emacs error, about environments, or emacs and [...]