If you want to create a new page, you can type the name of the new page into the search box at the top right. The search will yield all pages, which contain the text you searched for and in addition there will be a red link to create the page that you searched for and didn't find, since it doesn't exist yet.
File:Search.png|Result of search
Remember that you can always just copy from an example - at least that is what I usually do. There are useful help pages for [https://www.mediawiki.org/wiki/Help:Formatting formatting], [https://www.mediawiki.org/wiki/Help:Images adding pictures] and [https://www.mediawiki.org/wiki/Help:Links adding links].
If you find all of this too daunting, you can also just send your requested changes to email@example.com and I can add the text, pictures or videos to the wiki for you.