It sounds like what you need is WooCommerce. With WC you can create a product, set it as a ‘Variable Product’, and create individual variations with their own prices, SKUs etc. that customers will be able to choose from a dropdown in your store. As for importing data from a .CSV, there are plenty of plugins out there that will allow you to do this.
WordPress isn’t like Magento in that all it is is a website building tool. If you want to do more with your site, you need Plugins or custom code, the former being the much simpler solution.