Hi there, Pina!
SEO (Search Engine Optimization), a fancy way of saying "getting your site to the top of search engines!" is also a really great way to improve generating both sales and traffic! Pst, SEO features such as keywords, title tags, product titles and meta descriptions are provided by Shopify, in each pricing package – Use them! These features are magical and some really great advice on how you can use them is posted up on this link: http://docs.shopify.com/manual/settings/2-general/9-search-engine-optimization.
Also, try checking out any search engines' most popular keywords and start implementing them to your store. If the keywords you use are popular then your store is sure to see more traffic!
We also have quite a few blog posts surrounding SEO listed here.
Hope that steers in the right direction!
Lizbee is absolutely right. You need to first submit your website in different Search Engines for getting a better ranking. After that, just do SEO and SMM for better result in SERP. It is the best way to generate a number of traffic in your website.