If you want general advice on creating a conlang, I recommend David J. Peterson's series of videos on YouTube, entitled 'The Art of Language Invention'. A YouTube channel called Biblaridion also provides instructive videos.
Another useful piece of advice: learn another language.
If you want instructions for creating pages on this wiki, I suggest using one of the articles from the 'Spotlight' menu as a template. Create a new article by copying the Wiki code from one of those.
There are two views for editing: the 'Visual editor' allows you to edit the article without seeing it in code. The 'Source editing' is the Wiki code. There is a drop down menu at the top for changing between the two.