Do you have any experience in creating websites? If so, go with woocommerce (wordpress plugin and themes) or go with shopify ($29 monthly fee). If you want a ready store you can get one for cheap there are so many people around the web offering it as a service. If you want to learn, well,, you have a lot to learn.
Prestashop is also a very good solution that I use the last 5 years and its 100% free (it takes time to learn it). Magento is another profesional solution but needs a good programmer (which will cost in time).
There are many platforms to build your own ecommerce store. I have a store on WordPress+WooCommerce platform. It's free and has a lot of customization options. Shopify is also a great option but a tad bit pricey and the level of customization is lesser here. You'll have to pay for most of the options or tweaks for your store.
There are sites out there than give good advice. One site is UnderstandingE, and the content they have there is very good.
If you have knowledge of WordPress try WooCommerce. It's highly flexible with lots of features and functionalities. It's also fairly easy to work with and you can easily find help online.