Hello, I am in the process of creating my first website. I asked a friend to help me create a dynamic navigation where the user would select their state from a drop down, and than, another dropdown would populate with the counties of that state. He made this for me and sent it as:
1.) a .js file named jquerey-1.9.0
2.) a .ds_store file
3.) an html file

When I click on the html file he sent me I can see that the menu works perfectly the way I want it, unfortunately though, I know Nothing about javascript, nothing about .ds_store files and very little about .html files...I am not a coder, just a regular guy.

Anyways, my site is on WordPress foundation, how do I go about adding the navigation menu to my site, Where do I put it in Wordpress? I only had him add 2 states and 4 counties, how do I open it to see what it looks like so I can add more when needed? Do I need to add the .js file + the .ds_store file ++ the .html file ALL to my Wordpress site to get this working? I have added a dropbox link to what he sent me in case that helps. And please, if you are kind enough to answer me, explain it in a way even an idiot can understand

Also he sent me a folder named Mac_OSX, do I need to do anything with this? I'm working on a PC...

Dropbox Link: https://www.dropbox.com/sh/crot9fsisdkcdyi/SsZ4Tiix2K