We can only help you set up our version of the GA tracking code; we cannot provide support for setting up and using GA itself, so that would be up to you.
It appears your site has another GA plugin for WP installed, which would conflict with our version of the GA tracking code and modifies our cart button codes, so you will need to uninstall that plugin. If uninstalling that does not automatically restore your cart button codes to their original state, you may also need to recopy your Add to Cart button code from Seller Admin to repaste into your page; the top of this help page explains the proper way to modify our button codes to replace our standard button image with a custom button graphic:
http://www.e-junkie.com/ej/help.custom.purchase-buttons.htm
Also, it appears your page has two copies of our GA tracking code and View Cart script code; it would be best to remove the copy that's up in your page's HEAD section, and keep the copy that's down near the </body> tag.
Finally, your EJEJC_BEACON URL for AdWords should be a complete URL starting with "http://" (or "https://"), and using "&" rather than "& amp;" in the query string at the end.