The easiest way to get traffic to your store is to buy ads from Google or Facebook.
Unfortunately, this is also the most expensive way.
But there are other options:
Build a Google Sitemap and tell Google about your site: The sitemap plugin allows you to build an XML sitemap in the format Google uses. Once you have done that, go to Google Webmaster Tools, create an account and submit your sitemap. Note: don’t confuse the Google Sitemap (which is created in XML for consumption by computers) with the built-in sitemap for your Zen Cart (which is created in HTML for consumption by humans).
Build a community around your content: The blogging page offers some suggestions on doing this.
Participate in forums in your area of business, and add your URL to your forum signature. For example, if you sell plants, participate actively in gardening forums. Just be sure to follow community standards (don’t spam the forum with ads for your products, for example).
Also be sure you have done all the possible SEO Optimization possible for your site.