This page is in place just to let you create a new page which is not linked to from somewhere else. You can do it by the usual way - by putting your page title in double brackets. Then, when you click on the newly-created link, you'll be given the chance to create a new page. Note that this breaks the tree/branch structure of the wiki, so it would be preferable to create a link within an already existing page (assuming something relevant already exists); or, at least, do try to come back and see if something else is created to which you can link it.
Other ways to create blank pages: try searching for something. If it doesn't exist, the wiki will let you create it. But it'd be a good idea to link to it from somewhere else so as to not have orphan pages. You can also go to an address like http://www.cpcwiki.eu/index.php/ENTERYOURTOPICHERE. It will tell you that ENTERYOURTOPICHERE does not exist and will let you create it.