If you would like to edit Wikipedia, just click the [Edit] tab (to use VisualEditor which is a WYSIWYG editor) or click the [Edit source] tab to use the Wikipedia text editor. Both tabs are at the top of the desired page or page section.
To create a new article, type the name of the topic in the search box and press ↵ Enter. If a page doesn't already exist with that name, Wikipedia will let you create one. Follow the instructions on the screen. As an alternative, the Wikipedia Article Wizard helps you through the process of submitting a new article to Wikipedia. Redlinks are another way to create new articles. Mouse click on the red link and Wikipedia will let you create a new article with that name.
This page is written in British English, which has its own spelling conventions (colour, travelled, centre, defence, artefact, analyse) and some terms that are used in it may be different or absent from other varieties of English. According to the relevant style guide, this should not be changed without broad consensus.