Layout>Numbering and Section and pick a different Style.
There are some options available for different numbering formats and section prefixes in Pages Panel > Numbering & Section Options.
What sort of name did you have in mind? Where do you want the name to appear -- on the page itself, or in the panel?
The name I have in mind is: index.html
The reason is because I'm trying to build the app through Phonegap (build.phonegap), and the error I'm getting is the "index.html not found",
so I spoke to a Developer I found on the Phonegap site, and he said if the first page isn't named "index.html", that can be the problem.
So I'm not looking for a different 'style' of numbering, I'm looking to rename the first page to "index.html".
I think you misunderstood the instruction.
The first file on a website would be "index.html"
It's nothing to do with InDesign files - you shouldn't rename your indesign files.
This is an oversimplification: If you're exporting your home page as HTML from InDesign, name the file "index.html."
The default home page name "index.html" is really basic knowledge with respect to producing pages to be browser-rendered. It sounds like you might be in over your head a bit. Have a read around here: http://www.w3schools.com/html/