Download

You can review the SPA-Cart eCommerce CMS on CodeCanyon.net:
https://codecanyon.net/item/ajax-cart-very-fast-no-page-reloading-many-features-responsive-and-mobile-skin/17109430
Free SPA-Cart download and use is here(no license needed):
https://spa-cart.com/SpaCart_1.9.1.3.zip

It has a good SEO already:
View Google PageSpeed Insights

You don’t need to focus on optimizations – just set up your Title tag, Meta keywords and Meta description.