LaTeX was written for use with English, and so there are very few
language-specific issues facing authors in English. The main one
is hyphenation: UK and US traditions are different. LaTeX starts out
using US English patterns, but you can switch to UK ones using babel.
\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[UKenglish]{babel}
\begin{document}
Some text
\end{document}