How do I use a jQuery plugin?

How do I use a jQuery plugin?

Hi,

I am totally new to JavaScript and jQuery.
I would like to use this plugin https://harvesthq.github.io/chosen/ for a multiselect on a page.

How do I use the plugin?
So far I downloaded the chosen_v1.6.2.zip at https://github.com/harvesthq/chosen/releases, unzipped it, and added it to a js folder in my root.
I copied the source of the page https://harvesthq.github.io/chosen/ to my jsp file, prefixed all references to chosen files in the page with " js/chosen_v1.6.2/", and made the chosen files available as static files.

But when I look at the page, the multiple select "Into this" part is not as presented at https://harvesthq.github.io/chosen/

If I use the Chrome developer Tool to view errors, I get:
"Uncaught SyntaxError: Unexpected token <" for the "<" of the "<html>" tag, and
"Uncaught TypeError: $(...).chosen is not a function"

What am I doing wrong?

Thanks,
-Louise