The names you’re seeing are the RW generated, default names. When you add a new page, RW creates unique folder names, so that you don’t end up with one page overwriting another. Treat these as placeholders that you need to customize.
You should be changing the folder names to be representative of the content on your page. This is done in the General Settings of each page. You access the folder and filename settings in the first pane of the Page Inspector, which is usually docked on the right side of your window.
Leave the filename as either “index.html” or “index.php”. The links to pages on your website will be your website address plus the folder name(s). RW will leave off the page name from the URL and let the web server provide the correct file. This is very standard and considered best practice these days.
Always use lowercase for the file and folder names. Most web server’s file systems are case sensitive. This means that a folder named “Page” and one named “page” are two completely different folders. Windows and OS X are case insensitive and would that those as the same folder. Save yourself any headaches later and stick with lowercase, as it makes things easier.
While in the page’s General Settings, set the Browser Title for that page, as well.